阅读说明：本技术 可折叠电子设备 (Foldable electronic device ) 是由 王岩 刘华涛 应李俊 尤佳庆 余冬 李建铭 王汉阳 于 2019-10-31 设计创作，主要内容包括：本申请公开了一种可折叠电子设备,包括天线系统,天线系统包括天线地板、第一天线和第二天线。天线地板通过转轴分成相互展开或相互折叠的第一天线地板部分和第二天线地板部分。第一天线和第二天线分别对应第一天线地板部分和第二天线地板部分设置。第一天线包括第一天线辐射体和第一接地电容,第一天线辐射体具有第一枝节。第二天线包括第二天线辐射体和第二接地电容,第二天线辐射体具有第二枝节。本申请能够使一对天线：在展开状态时该对天线的两个天线分别独立工作；在折叠状态时,即使在该对天线的两个天线之间相隔较近甚至有部分重叠的情况下,该对天线的两个天线之间具有较高的隔离度和较低的包络相关性系数,依然正常工作。(The application discloses a foldable electronic device, comprising an antenna system, wherein the antenna system comprises an antenna floor, a first antenna and a second antenna. The antenna floor is divided by a rotating shaft into a first antenna floor part and a second antenna floor part which are unfolded or folded with each other. The first antenna and the second antenna are disposed corresponding to the first antenna floor part and the second antenna floor part, respectively. The first antenna comprises a first antenna radiator and a first grounding capacitor, and the first antenna radiator is provided with a first branch knot. The second antenna comprises a second antenna radiator and a second grounding capacitor, and the second antenna radiator is provided with a second branch knot. The present application enables a pair of antennas: when in the unfolding state, the two antennas of the pair of antennas respectively and independently work; when the folded antenna is folded, even under the condition that the two antennas of the pair of antennas are close to each other or even partially overlapped, the two antennas of the pair of antennas still work normally due to the fact that the two antennas of the pair of antennas have high isolation and low envelope correlation coefficients.)

1. A foldable electronic device comprising an antenna system, the antenna system comprising:

an antenna floor divided by a rotation shaft into a first antenna floor part and a second antenna floor part which are unfolded or folded with each other;

a first antenna including a first antenna radiator and a first ground capacitor, at least a portion of the first antenna radiator being located outside an edge of a side of the first antenna ground portion away from the rotation axis, the first antenna radiator including a first end and a second end, and having a first antenna feed point between said first and second ends and a first connection point between said first and second ends, a first antenna radiator portion between said first and second ends being a first stub, said first antenna feed point being connected to said first antenna ground portion by a first feed, the first antenna radiator is connected to the first antenna ground plate part at the first connecting point through the first grounding capacitor and forms a grounding point of the first grounding capacitor; the first antenna feed point and the grounding point of the first feed source are positioned on one side of the central line of the antenna floor, the first connecting point is closer to the central line relative to the first antenna feed point, and the grounding point of the first grounding capacitor is closer to the central line relative to the grounding point of the first feed source; wherein the central line is perpendicular to the axial direction of the rotating shaft;

a second antenna including a second antenna radiator and a second ground capacitor, at least a portion of the second antenna radiator being located outside an edge of a side of the second antenna floor portion away from the rotation axis, the second antenna radiator including a first end and a second end, and having a second antenna feed point between said first end and said second end and a second connection point between said second antenna feed point and said second end, a second antenna radiator section between said second connection point and said second end being a second stub, said second antenna feed point being connected to said second antenna floor section by a second feed, and forming a grounding point of the second feed source, wherein the second antenna radiator is connected to the second antenna floor part at the second connection point through the second grounding capacitor, and forms a grounding point of the second grounding capacitor; the second antenna feed point and the grounding point of the second feed source are positioned on the other side of the center line opposite to the one side, the second connection point is closer to the center line relative to the second antenna feed point, and the grounding point of the second grounding capacitor is closer to the center line relative to the grounding point of the second feed source.

2. The foldable electronic device of claim 1, wherein current through the first ground capacitor by the first antenna radiator forms a first floor current flowing in a first direction and a second floor current flowing in a second direction in the first antenna floor portion, the first direction and the second direction being opposite; the current flowing on the first branch forms a third floor current flowing towards the first direction on the first antenna floor part, and the magnitudes of the second floor current and the third floor current are approximately equal;

the second antenna radiator forms a fourth floor current flowing towards the first direction and a fifth floor current flowing towards the second direction on the second antenna floor part through the current of the second grounding capacitor, the current flowing on the second branch forms a sixth floor current flowing towards the second direction on the second antenna floor part, and the magnitudes of the fourth floor current and the sixth floor current are approximately equal.

3. The foldable electronic device of claim 1 or 2, wherein the first connection point, the first antenna feed point, the ground point of the first ground capacitor and the ground point of the first feed are located on one side of a virtual line, and the second connection point, the second antenna feed point, the ground point of the second ground capacitor and the ground point of the second feed are located on the other side of the virtual line; wherein the virtual line is the centerline or parallel to the centerline.

4. The foldable electronic device of any of claims 1-3, wherein the first antenna radiator further has a first predetermined point between the first antenna feed point and the first connection point, the distance between the first predetermined point and the first connection point being less than or equal to 10 mm; the second antenna radiator is also provided with a second preset point between the second antenna feed point and the second connection point, and the distance between the second preset point and the second connection point is less than or equal to 10 mm;

when the first antenna floor part and the second antenna floor part are folded with each other, in a direction parallel to the axial direction of the rotating shaft, the second end of the first antenna radiator extends to a position not exceeding the second preset point, and the second end of the second antenna radiator extends to a position not exceeding the first preset point.

5. The foldable electronic device of any one of claims 1-4, wherein an operating frequency band of the first antenna radiator and an operating frequency band of the second antenna radiator are the same or partially overlapping.

6. The foldable electronic device according to any of claims 1 to 5, wherein the operating frequency band of the first antenna radiator is 700-; the length of the first branch is 10-30mm, and the length of the second branch is 10-30 mm; the capacitance value of the first grounding capacitor is 1-5pF, and the capacitance value of the second grounding capacitor is 1-5 pF.

7. The foldable electronic device of any of claims 1-6, wherein the first antenna radiator extends in a straight line along the side edge of the first antenna floor section;

the second antenna radiator extends in a straight line along the side edge of the second antenna floor portion.

8. The foldable electronic device of any one of claims 1-6, wherein the first antenna radiator is further located near a diagonal corner of the first antenna floor portion away from the hinge and extends in a bent shape along a corner edge of the diagonal corner of the first antenna floor portion, and the first antenna radiator has a first straight line segment extending along the side edge of the first antenna floor portion, the first straight line segment including the first stub;

the second antenna radiator is further located near a diagonal of the second antenna floor portion away from the rotating shaft and extends in a bent shape along a corner edge of the diagonal of the second antenna floor portion, the second antenna radiator has a first straight line segment extending along the side edge of the second antenna floor portion, and the first straight line segment of the second antenna radiator includes the second stub;

the diagonal angle of the first antenna floor part is disposed opposite to the diagonal angle of the second antenna floor part when the first antenna floor part and the second antenna floor part are spread apart from each other.

9. The foldable electronic device of claim 8, wherein the first antenna radiator further comprises a second straight segment connected perpendicularly to an end of the first straight segment of the first antenna radiator distal from the first stub;

the second antenna radiator further comprises a second straight line section, and the second straight line section of the second antenna radiator is vertically connected to one end, far away from the second branch, of the first straight line section of the second antenna radiator.

10. The foldable electronic device of any one of claims 1-9, wherein the first ground capacitor and the second ground capacitor are both tunable capacitors, and wherein isolation and envelope correlation coefficients of the first antenna radiator and the second antenna radiator are adjusted by adjusting capacitance values of the first ground capacitor and the second ground capacitor.

11. The foldable electronic device of claim 10, wherein the first antenna further comprises a first switch connected between the first antenna radiator and the first antenna ground portion, the first antenna radiator operating in different sub-bands by switching of the first switch;

the second antenna further comprises a second switch, the second switch is connected between the second antenna radiator and the second antenna floor part, and the second antenna radiator works in different sub-frequency bands through switching of the second switch.

12. The foldable electronic device of claim 11, wherein the first switch and the second switch each employ a single-pole, multi-throw switch such that the first switch corresponds to a plurality of sub-bands in which the first antenna radiator operates and the second switch corresponds to a plurality of sub-bands in which the second antenna radiator operates.

13. The foldable electronic device of claim 12, wherein the plurality of sub-bands in which the first antenna radiator operates and the plurality of sub-bands in which the second antenna radiator operates each include a first sub-band, a second sub-band, a third sub-band, and a fourth sub-band;

the frequency range of the first sub-band is 704-788 MHz; the frequency range of the second sub-band is 791-; the frequency range of the third sub-band is 824-894 MHz; the frequency range of the fourth sub-band is 880-960 MHz.

14. The foldable electronic device of any one of claims 11-13, wherein a first antenna radiator portion located between the first antenna feed point and the first end of the first antenna radiator is a first extension, the first switch connected between the first extension and the first antenna ground portion;

a second antenna radiator portion located between the second antenna feed point and the first end of the second antenna radiator is a second extension segment, and the second switch is connected between the second extension segment and the second antenna floor portion.

Technical Field

The invention relates to the field of wireless communication antennas, in particular to foldable electronic equipment.

Background

After the mobile phone enters the smart era, the bar smart mobile phone has been in a mobile phone form for a long time in the consumer market. In order to bring more comfortable and convenient experience to mobile phone/mobile terminal device users, foldable smart phones are a popular topic at present. Various large mobile phone manufacturers, such as samsung, zhongxing, motorola, huashi, etc., have already released related foldable smart phones, while companies such as OPPO/VIVO, millet, apple, etc., are also in the popularity to release foldable smart phones.

The foldable smart phone has two or more working states, and two common working states are as follows: an unfolded state and a folded state. The unfolding state is the current common bar smart phone, and the folding state is the state that the bar smart phone is rotated 180 degrees along the rotating shaft to close the cover. For the antenna design of the foldable smart phone in the unfolded state, the design is similar to the current design of the bar smart phone, and the current design scheme can be adopted. However, for the antenna design in the folded state, the relative position between the antennas may change, and when the distance between the antennas is short, the isolation of the antennas is low, the Envelope Correlation Coefficient (ECC) is high, and the transmission/reception performance of the entire antenna apparatus may be degraded. Therefore, for the design of the antenna of the foldable smart phone in a folded state, the distance between each antenna is closer, and how to design a high isolation degree and a low envelope correlation coefficient is a difficult point and a pain point of the design of the antenna of the foldable smart phone.

Based on the difficulty and pain point of the foldable smart phone antenna design, in the antenna design of the foldable smart phone in the prior art, two antennas can work simultaneously usually in the unfolding state, and only one antenna can work normally in the folding state, so that the number of the antennas capable of working in the folding state of the foldable smart phone is reduced relative to the number of the antennas capable of working in the unfolding state.

For example, U.S. patent application US10079425B2 discloses an antenna device for a portable terminal, which is a foldable smart phone, as shown in fig. 1, the portable terminal 100 having the antenna device including a first antenna element 131 and a second antenna element 133 provided on a flexible display element. The display element includes a first region 101 and a second region 102 that can be folded to face each other. The first antenna element 131 is disposed on one side of the first region 101, and the second antenna element 133 is disposed on one side of the second region 102. The circuit board 103 is disposed in the central portion of the display element. Each of the first antenna element 131 and the second antenna element 133 extends in the longitudinal direction of the display element and in a direction away from the circuit board 103. The first antenna element 131 and the second antenna element 133 may at least partly overlap when the display element is in the folded state. When the display element is in the unfolded state, both the first antenna element 131 and the second antenna element 133 operate normally. When the display element is in the folded state, the switching element 135 is turned off, and the antenna device is configured as a monopole antenna formed by only the first antenna element 131, that is, only the first antenna element 131 is operated, and the second antenna element 133 is not operated.

Therefore, the portable terminal adopting the antenna device with the structure can have two antennas to work simultaneously when in the unfolding state, and only one antenna can work normally when in the folding state, thereby reducing the number of the antennas which can work when the portable terminal is in the folding state relative to the number of the antennas which can work when in the unfolding state.

Disclosure of Invention

The present application aims to solve the problem in the prior art that the number of antennas that can be operated in a folded state of a foldable electronic device is reduced relative to the number of antennas that can be operated in an unfolded state. Therefore, the embodiment of the present application provides a foldable electronic device, which overcomes the pain point and difficulty of the antenna design of the existing foldable electronic device, and can enable a pair of antennas to: when in the unfolding state, the two antennas of the pair of antennas respectively and independently work; in the folded state, even under the condition that the two antennas of the pair of antennas are close to each other or even partially overlapped (not contacted), the two antennas of the pair of antennas still work normally with high isolation and low Envelope Correlation Coefficient (ECC), namely, the self-decoupling of the pair of antennas is realized.

An embodiment of the present application provides a foldable electronic device, including an antenna system, the antenna system includes:

an antenna floor divided by a rotation shaft into a first antenna floor part and a second antenna floor part which are unfolded or folded with each other;

a first antenna including a first antenna radiator and a first ground capacitor, at least a portion of the first antenna radiator being located outside an edge of a side of the first antenna ground portion away from the rotation axis, the first antenna radiator including a first end and a second end, and having a first antenna feed point between said first and second ends and a first connection point between said first and second ends, a first antenna radiator portion between said first and second ends being a first stub, said first antenna feed point being connected to said first antenna ground portion by a first feed, the first antenna radiator is connected to the first antenna ground plate part at the first connecting point through the first grounding capacitor and forms a grounding point of the first grounding capacitor; the first antenna feed point and the grounding point of the first feed source are positioned on one side of the central line of the antenna floor, the first connecting point is closer to the central line relative to the first antenna feed point, and the grounding point of the first grounding capacitor is closer to the central line relative to the grounding point of the first feed source; wherein the central line is perpendicular to the axial direction of the rotating shaft;

a second antenna including a second antenna radiator and a second ground capacitor, at least a portion of the second antenna radiator being located outside an edge of a side of the second antenna floor portion away from the rotation axis, the second antenna radiator including a first end and a second end, and having a second antenna feed point between said first end and said second end and a second connection point between said second antenna feed point and said second end, a second antenna radiator section between said second connection point and said second end being a second stub, said second antenna feed point being connected to said second antenna floor section by a second feed, and forming a grounding point of the second feed source, wherein the second antenna radiator is connected to the second antenna floor part at the second connection point through the second grounding capacitor, and forms a grounding point of the second grounding capacitor; the second antenna feed point and the grounding point of the second feed source are positioned on the other side of the center line opposite to the one side, the second connection point is closer to the center line relative to the second antenna feed point, and the grounding point of the second grounding capacitor is closer to the center line relative to the grounding point of the second feed source.

In the foldable electronic device of the present application, the pain point and difficulty of the existing foldable electronic device antenna design are overcome, the first antenna floor part is connected to through the first ground capacitor at the proper position of the first antenna radiator, and the first stub is arranged, and simultaneously, the second antenna floor part is connected to through the second ground capacitor at the proper position of the second antenna radiator, and the second stub is arranged, so that a pair of antennas can be made: when the antenna floor is in an unfolded state, the first antenna radiator and the second antenna radiator can work independently, and when the antenna floor is in a folded state, even under the condition that the first antenna radiator and the second antenna radiator are close to each other or even partially overlapped (but not in contact), the first antenna radiator and the second antenna radiator have high isolation and low Envelope Correlation Coefficient (ECC), so that the radiation efficiency and the diversity gain of the antenna are improved, the first antenna radiator and the second antenna radiator still work normally, and the self-decoupling of the pair of antennas is realized.

In some embodiments, current through the first ground capacitor by the first antenna radiator forms a first ground current flowing in a first direction and a second ground current flowing in a second direction in the first antenna ground portion, the first direction and the second direction being opposite; the current flowing on the first branch forms a third floor current flowing towards the first direction on the first antenna floor part, and the magnitudes of the second floor current and the third floor current are approximately equal;

the second antenna radiator forms a fourth floor current flowing towards the first direction and a fifth floor current flowing towards the second direction on the second antenna floor part through the current of the second grounding capacitor, the current flowing on the second branch forms a sixth floor current flowing towards the second direction on the second antenna floor part, and the magnitudes of the fourth floor current and the sixth floor current are approximately equal.

In this solution, the second and third floor currents are substantially equal in magnitude and opposite in direction, such that little floor current flows in the first antenna ground portion in the second direction, while the fourth and sixth floor currents are substantially equal in magnitude and opposite in direction, such that little floor current flows in the second antenna ground portion in the first direction, such that a high isolation and a low Envelope Correlation Coefficient (ECC) are obtained between the first and second antenna radiators in the folded state.

In some embodiments, the first connection point, the first antenna feed point, the ground point of the first ground capacitor, and the ground point of the first feed are located on one side of a virtual line, and the second connection point, the second antenna feed point, the ground point of the second ground capacitor, and the ground point of the second feed are located on the other side of the virtual line; wherein the virtual line is the centerline or parallel to the centerline.

In this aspect, with the above-described structure, it is possible to reduce the current intensity at which the floor current formed by the first antenna radiator on the first antenna floor portion and the floor current formed by the second antenna radiator on the second antenna floor portion overlap in the folded state, thereby avoiding deterioration of the isolation and the envelope correlation coefficient between the first antenna radiator and the second antenna radiator when in use.

In some possible embodiments, when the first antenna floor part and the second antenna floor part are folded over each other, the first connection point is at a distance from the first antenna feed point that is smaller than a distance from the second connection point to the first antenna feed point, and the grounding point of the first ground capacitor is at a distance from the grounding point of the first feed that is smaller than a distance from the grounding point of the second ground capacitor to the grounding point of the first feed. The distance from the second connecting point to the second antenna feeding point is smaller than that from the first connecting point to the second antenna feeding point, and the distance from the grounding point of the second grounding capacitor to the grounding point of the second feed source is smaller than that from the grounding point of the first grounding capacitor to the grounding point of the second feed source.

In some embodiments, the first antenna radiator further has a first predetermined point between the first antenna feed point and the first connection point, the first predetermined point being less than or equal to 10mm from the first connection point; the second antenna radiator is also provided with a second preset point between the second antenna feed point and the second connection point, and the distance between the second preset point and the second connection point is less than or equal to 10 mm;

when the first antenna floor part and the second antenna floor part are folded with each other, in a direction parallel to the axial direction of the rotating shaft, the second end of the first antenna radiator extends to a position not exceeding the second preset point, and the second end of the second antenna radiator extends to a position not exceeding the first preset point.

In this aspect, with the above-described configuration, it is possible to further reduce the current intensity at which the floor current formed by the first antenna radiator on the first antenna floor portion and the floor current formed by the second antenna radiator on the second antenna floor portion overlap in the folded state, thereby avoiding deterioration of the isolation and the envelope correlation coefficient between the first antenna radiator and the second antenna radiator when in use.

In some possible embodiments, the distance between the first preset point and the first connection point is less than or equal to 2 mm; the distance between the second preset point and the second connecting point is less than or equal to 2 mm.

In some possible embodiments, when the first antenna floor part and the second antenna floor part are folded over each other, a first antenna radiator part between the first predetermined point and the second end of the first antenna radiator is overlapped with or separated from a second antenna radiator part between the second predetermined point and the second end of the second antenna radiator, and a first antenna radiator part between the first predetermined point and the first end of the first antenna radiator is separated from a second antenna radiator part between the second predetermined point and the first end of the second antenna radiator, in a direction parallel to the axial direction of the rotating shaft.

In some embodiments, the operating frequency band of the first antenna radiator and the operating frequency band of the second antenna radiator are the same or partially overlapping.

In some embodiments, the operating frequency band of the first antenna radiator is 700-; the length of the first branch is 10-30mm, and the length of the second branch is 10-30 mm; the capacitance value of the first grounding capacitor is 1-5pF, and the capacitance value of the second grounding capacitor is 1-5 pF.

In some embodiments, the first antenna radiator extends in a straight line along the side edge of the first antenna floor portion; the second antenna radiator extends in a straight line along the side edge of the second antenna floor portion.

In some embodiments, the first antenna radiator is further located near a diagonal corner of the first antenna ground portion away from the rotation axis and extends in a bent shape along a corner edge of the diagonal corner of the first antenna ground portion, and the first antenna radiator has a first straight line segment extending along the side edge of the first antenna ground portion, the first straight line segment including the first branch;

the second antenna radiator is further located near a diagonal of the second antenna floor portion away from the rotating shaft and extends in a bent shape along a corner edge of the diagonal of the second antenna floor portion, the second antenna radiator has a first straight line segment extending along the side edge of the second antenna floor portion, and the first straight line segment of the second antenna radiator includes the second stub;

the diagonal angle of the first antenna floor part is disposed opposite to the diagonal angle of the second antenna floor part when the first antenna floor part and the second antenna floor part are spread apart from each other.

In some embodiments, the first antenna radiator further comprises a second straight line segment connected perpendicularly to an end of the first straight line segment of the first antenna radiator distal from the first stub;

the second antenna radiator further comprises a second straight line section, and the second straight line section of the second antenna radiator is vertically connected to one end, far away from the second branch, of the first straight line section of the second antenna radiator.

In some embodiments, the first ground capacitor and the second ground capacitor are both adjustable capacitors, and the isolation and the envelope correlation coefficient of the first antenna radiator and the second antenna radiator are adjusted by adjusting capacitance values of the first ground capacitor and the second ground capacitor. Therefore, the capacitance values of the first grounding capacitor and the second grounding capacitor can be respectively adjusted to be respectively matched with the lengths of the first branch and the second branch, so that the isolation between the first antenna radiator and the second antenna radiator is higher and the enveloping correlation coefficient is lower.

In some embodiments, the first antenna further comprises a first switch, the first switch is connected between the first antenna radiator and the first antenna ground plate portion, and the first antenna radiator operates in different sub-bands by switching of the first switch; the second antenna further comprises a second switch, the second switch is connected between the second antenna radiator and the second antenna floor part, and the second antenna radiator works in different sub-frequency bands through switching of the second switch.

By switching the first switch and the second switch, the working frequency bands of the first antenna radiator and the second antenna radiator can be switched into different sub-frequency bands according to actual use requirements. When the antenna works in different frequency bands, in order to realize the optimal isolation and Envelope Correlation Coefficient (ECC), the first grounding capacitor and the second grounding capacitor also work in corresponding capacitance values. That is to say, can switch through the switch and work at different frequency channels to realize that each frequency channel all has the performance of similar expansion state under the folded condition.

In some embodiments, the first switch and the second switch are both single-pole multi-throw switches, such that the first switch corresponds to a plurality of sub-bands in which the first antenna radiator operates, and the second switch corresponds to a plurality of sub-bands in which the second antenna radiator operates.

In some embodiments, the plurality of sub-bands in which the first antenna radiator operates and the plurality of sub-bands in which the second antenna radiator operates each include a first sub-band, a second sub-band, a third sub-band, and a fourth sub-band;

the frequency range of the first sub-band is 704-788 MHz; the frequency range of the second sub-band is 791-; the frequency range of the third sub-band is 824-894 MHz; the frequency range of the fourth sub-band is 880-960 MHz.

In some embodiments, a first antenna radiator portion between the first antenna feed point and the first end of the first antenna radiator is a first extension, the first switch is connected between the first extension and the first antenna ground portion; a second antenna radiator portion located between the second antenna feed point and the first end of the second antenna radiator is a second extension segment, and the second switch is connected between the second extension segment and the second antenna floor portion.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural view of a conventional portable terminal having an antenna device, in which a left side view is a schematic structural view of the portable terminal in an unfolded state and a right side view is a schematic structural view of the portable terminal in a folded state;

fig. 2a is a schematic structural diagram of an embodiment of an antenna system of a foldable electronic device according to an embodiment of the present application, wherein the antenna floor is in an unfolded state;

fig. 2b is a schematic structural diagram of an embodiment of an antenna system of a foldable electronic device according to an embodiment of the present application, wherein the antenna floor is in a folded state;

fig. 3a is a graph illustrating S-parameter performance simulation curves of the first antenna radiator and the second antenna radiator within the working frequency range, measured when the antenna floor of the antenna system of the foldable electronic device of the embodiment of the application is in the two states, namely the unfolded state and the folded state, where the frequency range of the working frequency ranges of the first antenna radiator and the second antenna radiator is 824-894 MHz;

fig. 3b is a simulation graph of ECC (envelope correlation coefficient) parameter performance of the first antenna radiator and the second antenna radiator within the working frequency range measured when the antenna floor of the antenna system of the foldable electronic device of the embodiment of the application is in the two states, i.e., the unfolded state and the folded state, where the frequency range of the working frequency range of the first antenna radiator and the second antenna radiator is 824-894 MHz;

fig. 4a is a schematic structural diagram of an antenna system of a first reference design, in which a first branch and a second branch are removed on the basis of the antenna system of the present application;

fig. 4b is a schematic structural diagram of an antenna system designed by the second reference, in which the first ground capacitor and the second ground capacitor are removed on the basis of the antenna system of the present application, so that the first antenna radiator and the second antenna radiator are directly connected to the antenna floor through the connecting rib;

fig. 4c is a schematic structural diagram of an antenna system of a third reference design, in which a first branch and a second branch are removed, and a first ground capacitor and a second ground capacitor are removed on the basis of the antenna system of the present application, so that the first antenna radiator and the second antenna radiator are directly connected to an antenna floor through a connecting rib;

fig. 5a is a graph showing simulation curves of S-parameter performance of the first antenna radiator and the second antenna radiator within the working frequency range, measured when the antenna floor of the antenna system of the present application and the three reference designs is in a folded state, where the frequency ranges of the working frequency ranges of the first antenna radiator and the second antenna radiator of the antenna system of the present application and the three reference designs are 824-894 MHz;

fig. 5b is a graph showing performance simulation curves of ECC (envelope correlation coefficient) parameters of the first antenna radiator and the second antenna radiator within the working frequency range, measured when the antenna floor of the antenna system of the present application and the three reference designs is in a folded state, where the frequency range of the working frequency ranges of the first antenna radiator and the second antenna radiator of the antenna system of the present application and the three reference designs is 824-894 MHz;

fig. 6a is a partial structural schematic diagram of an embodiment of an antenna system of a foldable electronic device according to an embodiment of the present application, in which only a first antenna is retained and a floor of the antenna is in an unfolded state;

fig. 6b is a partial structural diagram of the antenna system of the first reference design, in which only the first antenna remains and the antenna floor is in an unfolded state;

fig. 6c is a partial structural diagram of an antenna system of a second reference design, in which only the first antenna remains and the antenna floor is in an unfolded state;

fig. 7 a-7 c are schematic diagrams of current distribution on the antenna floor of the antenna system of the present application, the first reference design and the second reference design of the antenna system of fig. 6 a-6 c at the same operating frequency, respectively;

fig. 8 is a schematic diagram of an equivalent current distribution of a first antenna radiator of the antenna system of fig. 6a on an antenna floor;

fig. 9 is a schematic structural diagram of another embodiment of an antenna system of a foldable electronic device according to an embodiment of the present application, wherein an antenna floor is in an unfolded state;

fig. 10a is a graph illustrating S-parameter performance simulation curves of three operating sub-bands of a first antenna radiator and a second antenna radiator measured when an antenna system of a foldable electronic device according to an embodiment of the present application is in a folded state of an antenna floor;

fig. 10b is a graph illustrating an ECC parameter performance simulation of three sub-bands in which the first antenna radiator and the second antenna radiator operate, measured when the antenna system of the foldable electronic device according to the embodiment of the present application is in the folded state of the antenna floor.

Description of reference numerals:

the prior art is as follows:

100: a portable terminal;

101: first region

102: second region

103: circuit board

131: first antenna element

133: second antenna element

135: switching element

The application:

100: an antenna system;

200: an antenna floor; 210: a first antenna ground plate portion; 212: an upper side edge; 214: a diagonal; 220: a second antenna floor section; 222: a lower side edge; 224: a diagonal; 230: a rotating shaft;

300: a first antenna;

400: a first antenna radiator; 402: a first antenna feed point; 404: a first connection point; 406: a first branch section; 408: a first straight line segment; 410: a second straight line segment; 412: a first end; 414: a second end; 416: a first preset point;

420: a first ground capacitor; 422: a ground point of the first ground capacitor;

440: a first feed source; 442: a ground point of the first feed;

500: a second antenna;

600: a second antenna radiator; 602: a second antenna feed point; 604: a second connection point; 606: a second branch knot; 608: a first straight line segment; 610: a second straight line segment; 612: a first end; 614: a second end; 616: a second preset point;

620: a second ground capacitor; 622: a ground point of the second ground capacitor;

640: a second feed source; 642: a ground point of the second feed;

700: a first switch; 720: a first capacitor; 740: a first inductor;

800: a second switch; 820: a second capacitor; 840: a second inductor;

o1: a centerline;

o2: an axial direction;

d 1: a length of the first straight line segment;

d 11: the length of the other part of the first straight line segment except the first branch;

d 12: the length of the first branch;

d 13: the distance between one end of the first straight line section, which is far away from the first branch knot, and the left side edge of the first antenna floor part;

d 14: the distance of the first connection point from the center line;

d 15: the distance from one end of the first branch to the center line;

d 2: the length of the second straight line segment;

d 21: the second straight line section is connected with the distance from one end of the first straight line section to the first antenna feeding point;

d 22: the distance from the first antenna feeding point to one end, far away from the first straight line segment, of the second straight line segment;

d 23: the distance between the first connecting point and the grounding point of the first grounding capacitor;

d 3: a length of the first antenna floor section;

d 4: a width of the first antenna floor portion.

Detailed Description

The following description of the embodiments of the present application is provided by way of specific examples, and other advantages and effects of the present application will be readily apparent to those skilled in the art from the disclosure herein. While the description of the present application will be described in conjunction with the preferred embodiments, it is not intended that the features of the present application be limited to this embodiment. On the contrary, the application of the present disclosure with reference to the embodiments is intended to cover alternatives or modifications as may be extended based on the claims of the present disclosure. In the following description, numerous specific details are included to provide a thorough understanding of the present application. The present application may be practiced without these particulars. Moreover, some of the specific details have been omitted from the description in order to avoid obscuring or obscuring the focus of the present application. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that in this specification, like reference numerals and letters refer to like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

The technical solutions of the present application will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

A foldable electronic device is provided that includes an antenna system. In this embodiment, the foldable electronic device is exemplified by a foldable smart phone. Of course, it will be understood by those skilled in the art that in alternative embodiments, the foldable electronic device may be other foldable electronic devices such as a foldable tablet computer or a foldable smart watch, and the like, which does not limit the scope of the present application.

Referring to fig. 2 a-2 b, fig. 2a shows a schematic structure of an embodiment of the antenna system 100 of the foldable electronic device according to the embodiment of the present application, wherein the antenna floor 200 is in an unfolded state, and at this time, the first antenna floor part 210 and the second antenna floor part 220 of the antenna floor 200 are unfolded from each other. Fig. 2b shows a schematic structure of the antenna system 100 according to an embodiment of the present application, wherein the antenna floor 200 is in a folded state, in which the first antenna floor part 210 and the second antenna floor part 220 of the antenna floor 200 are folded over each other. The antenna system 100 is applied to a foldable electronic device. The foldable electronic device may be a foldable smart phone, a foldable tablet computer, or a foldable smart watch, etc.

As shown in fig. 2 a-2 b, the antenna system 100 comprises an antenna floor 200, a first antenna 300 and a second antenna 500. The antenna floor 200 is divided into a first antenna floor part 210 and a second antenna floor part 220, which are unfolded or folded with each other, by a rotation shaft 230. The first antenna 300 is disposed corresponding to the first antenna floor part 210, and the second antenna 500 is disposed corresponding to the second antenna floor part 220.

As shown in fig. 2a, when the antenna floor 200 is in the unfolded state, that is, the first antenna floor part 210 and the second antenna floor part 220 are unfolded from each other, the first antenna floor part 210 and the second antenna floor part 220 are located on the same plane, and the first antenna 300 is located outside of one side edge (i.e., the upper side edge 212 in fig. 2a) of the first antenna floor part 210 away from the rotation axis 230, and the second antenna 500 is located outside of one side edge (i.e., the lower side edge 222 in fig. 2a) of the second antenna floor part 220 away from the rotation axis 230. That is, when the antenna floor 200 is in the unfolded state, the first antenna 300 and the second antenna 500 are respectively located at two opposite side edges of the antenna floor 200 (i.e. the upper side edge 212 and the lower side edge 222 of the antenna floor 200 in fig. 2a, the upper side edge 212 is located at the first antenna floor part 210, and the lower side edge 222 is located at the second antenna floor part 220) away from the rotation axis 230, that is, the first antenna 300 is located at the top of the first antenna floor part 210, and the second antenna 500 is located at the bottom of the second antenna floor part 220.

As shown in fig. 2b, when the antenna floor 200 is in a folded state, i.e., the first antenna floor part 210 and the second antenna floor part 220 are folded each other, the first antenna floor part 210 and the second antenna floor part 220 are oppositely disposed, and the upper side edge 212 of the first antenna floor part 210 and the lower side edge 222 of the second antenna floor part 220 are oppositely disposed in a direction perpendicular to the antenna floor 200. At this time, the first antenna 300 and the second antenna 500 are located outside the same side of the antenna floor 200 facing away from the rotation axis 230, and the distance between the first antenna 300 and the second antenna 500 is relatively close, but the first antenna 300 and the second antenna 500 are not in contact.

Specifically, as shown in fig. 2a, the center line O1 of the antenna floor 200 is perpendicular to the axial direction O2 of the rotation shaft 230. The first antenna floor part 210 and the second antenna floor part 220 are divided into two parts, which are symmetrical and identical (including identical in structure and size), respectively, by a center line O1.

Further, the first antenna floor part 210 and the second antenna floor part 220, into which the antenna floor 200 is divided by the rotation shaft 230, are symmetrical with respect to the rotation shaft 230, and the first antenna floor part 210 and the second antenna floor part 220 are identical in structure and size. It should be noted that, as will be understood by those skilled in the art, the first antenna floor portion 210 and the second antenna floor portion 220 may have different structures and different sizes, and may be arranged according to actual needs, and the protection scope of the present application is not limited herein.

In the present embodiment, the antenna floor 200 has a square plate-like structure. It should be noted that the antenna floor 200 may be configured in other suitable shapes as will be appreciated by those skilled in the art.

In this embodiment, the antenna floor 200 may be formed by a bottom panel of a middle frame of a foldable electronic device (i.e., a foldable smart phone). Those skilled in the art will appreciate that in alternative embodiments, the antenna floor 200 may be constructed from other metal parts, such as a printed circuit board.

As shown in fig. 2a, the first antenna 300 includes a first antenna radiator 400 and a first ground capacitor 420. A portion of the first antenna radiator 400 is located outside a side edge (i.e. the upper side edge 212 in fig. 2a) of the first antenna floor section 210 remote from the rotation axis 230. That is, a part of the first antenna radiator 400 is located outside the upper side edge 212 of the first antenna floor part 210 facing away from the rotating shaft 230, and the extending direction of the upper side edge 212 is parallel to the axial direction O2 of the rotating shaft 230. As can be seen from fig. 2a, the other side edges (including the left and right side edges and the lower side edge) of the first antenna ground plate portion 210 are adjacent to the rotation axis 230.

The first antenna radiator 400 includes a first end 412 and a second end 414 and has a first antenna feed point 402 between the first end 412 and the second end 414 and a first connection point 404 between the first antenna feed point 402 and the second end 414. The first antenna radiator portion, which is located between the first connection point 404 and the second end 414, is a first branch 406.

The first antenna feed point 402 is connected to the first antenna floor section 210 by a first feed 440 and forms a first feed ground point 442. The first antenna radiator 400 is connected to the first antenna floor section 210 at the first connection point 404 via a first grounded capacitor 420 and forms a grounded point 422 of the first grounded capacitor. The first antenna feed point 402 and the first feed ground point 442 are located on one side of the centerline O1 of the antenna floor 200. The first connection point 404 is closer to the centerline O1 than the first antenna feed point 402, and the ground point 422 of the first ground capacitance is closer to the centerline O1 than the ground point 442 of the first feed.

Specifically, both ends of the first ground capacitor 420 are connected to the first antenna radiator 400 and the first antenna floor part 210, respectively. The first antenna radiator 400 can convert an alternating current in a metal body into a spatial electromagnetic wave or convert a spatial electromagnetic wave into an alternating current signal in a metal body, thereby transmitting or receiving an electromagnetic wave signal.

The first antenna feed point 402 and the first feed ground point 442 are located on one side of the centerline O1 of the antenna floor 200. As shown in fig. 2a, in this embodiment the first antenna feed point 402 and the first feed ground point 442 are located to the left of the centre line O1. Those skilled in the art will appreciate that in alternative other embodiments, the first antenna feed point 402 and the first feed ground point 442 may also be located to the right of the centerline O1.

Further, the first connection point 404 of the first antenna radiator 400 to the first ground capacitor 420 is closer to the center line O1 than the first antenna feeding point 402. That is, the first connection point 404 is a distance from the centerline O1 that is less than the distance of the first antenna feed point 402 from the centerline O1. In the present embodiment, the first connection point 404 is located on the left side of the center line O1. Those skilled in the art will appreciate that in alternative embodiments, the first connection point 404 may be located to the right of the centerline O1.

The first ground capacitor 420 connects the ground point 422 of the first ground capacitor formed by the first antenna ground section 210 closer to the center line O1 than the ground point 442 of the first feed. That is, the distance of the ground point 422 of the first ground capacitance from the centerline O1 is less than the distance of the ground point 442 of the first feed from the centerline O1. In the present embodiment, the ground point 422 of the first ground capacitor is located on the left side of the center line O1. It will be appreciated by those skilled in the art that in alternative embodiments, the ground point 422 of the first ground capacitor may also be located to the right of the centerline O1.

Further, the first antenna radiator part located between the first connection point 404 and the second end 414 of the first antenna radiator 400 (i.e. the right end in fig. 2a) is a first branch 406, wherein the second end 414 of the first antenna radiator 400 and the first antenna feeding point 402 are located on opposite sides of the first connection point 404 on the first antenna radiator 400. In the present embodiment, an end of the first branch 406 away from the first connection point 404 (i.e. a right end of the first branch 406 in fig. 2a, i.e. the second end 414) extends to the right side of the rotation shaft 230. It will be appreciated by those skilled in the art that in alternative embodiments, the end of the first branch 406 remote from the first connection point 404 (i.e., the right end in fig. 2a, i.e., the second end 414) may extend only to the left side of the rotation shaft 230.

As shown in fig. 2a, the second antenna 500 includes a second antenna radiator 600 and a second ground capacitor 620. A portion of the second antenna radiator 600 is located outside of a side edge (i.e., the lower side edge 222 in fig. 2a) of the second antenna floor portion 220 away from the rotation axis 230. That is, a portion of the second antenna radiator 600 is located outside the lower edge 222 of the second antenna floor portion 220 facing away from the rotating shaft 230, and the extending direction of the lower edge 222 is parallel to the axial direction O2 of the rotating shaft 230. As can be seen from fig. 2a, the other side edges (including the left and right side edges and the upper side edge) of the second antenna floor part 220 are adjacent to the rotation shaft 230.

The second antenna radiator 600 includes a first end 612 and a second end 614 and has a second antenna feed point 602 between the first end 612 and the second end 614 and a second connection point 604 between the second antenna feed point 602 and the second end 614. The portion of the second antenna radiator located between the second connection point 604 and the second end 614 is a second branch 606.

The second antenna feed point 602 is connected to the second antenna floor section 220 via a second feed 640 and forms a second feed ground point 642. The second antenna radiator 600 is connected to the second antenna floor section 220 at a second connection point 604 via a second ground capacitor 620 and forms a ground point 622 of the second ground capacitor. The second antenna feed point 602 and the second feed ground point 642 are located on the other side of the centre line O1, opposite to the one side. The second connection point 604 is closer to the centre line O1 than the second antenna feed point 602 and the ground point 622 of the second ground capacitance is closer to the centre line O1 than the ground point 642 of the second feed.

Specifically, both ends of the second ground capacitor 620 are connected to the second antenna radiator 600 and the second antenna floor part 220, respectively. The second antenna radiator 600 can convert an alternating current in a metal body into a spatial electromagnetic wave or a spatial electromagnetic wave into an alternating current signal in a metal body, thereby transmitting or receiving an electromagnetic wave signal.

The second antenna feed point 602 and the second feed ground point 642 are located on the other side of the centre line O1, opposite to the one side. As shown in fig. 2a, in this embodiment the second antenna feed point 602 and the ground point 642 of the second feed are located to the right of the centre line O1. It will be appreciated by those skilled in the art that in alternative other embodiments the second antenna feed point 602 and the second feed ground point 642 may also be located to the left of the centerline O1, in which case the first antenna feed point 402 and the first feed ground point 442 are located to the right of the centerline O1.

A second connection point 604 of the second antenna radiator 600 to the second ground capacitor 620 is closer to the center line O1 than the second antenna feed point 602. That is, the second connection point 604 is a smaller distance from the centerline O1 than the second antenna feed point 602 is from the centerline O1. In the present embodiment, the second connection point 604 is located on the right side of the center line O1. Those skilled in the art will appreciate that in alternative other embodiments, the second connection point 604 may also be located to the left of the centerline O1.

The second ground capacitance 620 connects the ground point 622 of the second ground capacitance formed by the second antenna floor section 220 closer to the centre line O1 than the ground point 642 of the second feed. That is, the distance of the ground point 622 of the second ground capacitance from the center line O1 is smaller than the distance of the ground point 642 of the second feed from the center line O1. In the present embodiment, the grounding point 622 of the second ground capacitor is located on the right side of the center line O1. It will be appreciated by those skilled in the art that in alternative embodiments, the grounding point 622 of the second grounded capacitor may also be located to the left of the centerline O1.

The portion of the second antenna radiator 600 located between the second connection point 604 and one end of the second antenna radiator 600 is a second branch 606, where one end of the second antenna radiator 600 and the second antenna feed point 602 are located on two opposite sides of the second connection point 604 on the second antenna radiator 600. In the present embodiment, an end of the second branch 606 away from the first connection point 404 (i.e. a left end of the second branch 606 in fig. 2a, i.e. the second end 614) extends to the right side of the rotation shaft 230. It will be appreciated by those skilled in the art that in alternative embodiments, the end of the first branch 406 away from the first connection point 404 (i.e., the left end in fig. 2a, i.e., the second end 614) may extend only to the left side of the rotation shaft 230.

The first connection point 404, the first antenna feed point 402, the ground point 422 of the first ground capacitor and the ground point 442 of the first feed are located on one side of a virtual line, and the second connection point 604, the second antenna feed point 602, the ground point 622 of the second ground capacitor and the ground point 642 of the second feed are located on the other side of the virtual line; the virtual line is the center line O1 or parallel to the center line O1. This can reduce the intensity of the current at which the floor current formed by the first antenna radiator 400 on the first antenna floor part 210 overlaps the floor current formed by the second antenna radiator 600 on the second antenna floor part 220 in the folded state, thereby avoiding deterioration of the isolation and the envelope correlation coefficient between the first antenna radiator 400 and the second antenna radiator 600 in use.

As shown in fig. 2b, when the antenna floor 200 is in a folded state, i.e. the first antenna floor part 210 and the second antenna floor part 220 are folded over each other, the first connection point 404 is at a smaller distance from the first antenna feed point 402 than the second connection point 604 is at from the first antenna feed point 402, and the grounding point 422 of the first ground capacitor is at a smaller distance from the grounding point 442 of the first feed than the grounding point 622 of the second ground capacitor is at from the grounding point 442 of the first feed. Meanwhile, the distance of the second connection point 604 from the second antenna feeding point 602 is smaller than the distance of the first connection point 404 from the second antenna feeding point 602, and the distance of the grounding point 622 of the second ground capacitor from the grounding point 642 of the second feed is smaller than the distance of the grounding point 422 of the first ground capacitor from the grounding point 642 of the second feed.

That is, when the antenna floor 200 is in a folded state, that is, the first antenna floor part 210 and the second antenna floor part 220 are folded with each other, the second connection point 604 and the first antenna feeding point 402 are located on both sides of the first connection point 404, respectively, and the grounding point 622 of the second ground capacitor and the grounding point 442 of the first feed are located on both sides of the grounding point 422 of the first ground capacitor, respectively, in a direction parallel to the axial direction O2 of the rotation shaft 230. Meanwhile, in the direction parallel to the axial direction O2 of the rotating shaft 230, the first connection point 404 and the second antenna feeding point 602 are respectively located at two sides of the second connection point 604, and the grounding point 422 of the first ground capacitor and the grounding point 642 of the second feed are respectively located at two sides of the grounding point 622 of the second ground capacitor. That is, when the antenna floor 200 is in the folded state, the first ground capacitor 420 and the second ground capacitor 620 are spaced apart from each other in a direction parallel to the axial direction O2 of the rotation shaft 230 and do not intersect each other.

Further, the first antenna radiator 400 also has a first predetermined point 416 between the first antenna feeding point 402 and the first connection point 404, and the distance between the first predetermined point 416 and the first connection point 404 is less than or equal to 10 mm. The second antenna radiator 600 further has a second predetermined point 616 between the second antenna feed point 602 and the second connection point 604, the distance between the second predetermined point 616 and the second connection point 604 being smaller than or equal to 10 mm. When the first antenna floor part 210 and the second antenna floor part 220 are folded with each other, the second end 414 of the first antenna radiator 400 extends to a position not exceeding the second preset point 616 and the second end 614 of the second antenna radiator 600 extends to a position not exceeding the first preset point 416 in a direction parallel to the axial direction O2 of the rotation shaft 230.

With the above-described structure, it is possible to reduce the current intensity at which the floor current formed by the first antenna radiator 400 on the first antenna floor part 210 and the floor current formed by the second antenna radiator 600 on the second antenna floor part 220 overlap in the folded state, thereby avoiding deterioration of the isolation and the envelope correlation coefficient between the first antenna radiator 400 and the second antenna radiator 600 in use.

Further, the distance between the first preset point 416 and the first connection point 404 is less than or equal to 2 mm. The distance between the second preset point 616 and the second connection point 604 is less than or equal to 2 mm. This can further avoid deterioration of the isolation and the envelope correlation coefficient between the first antenna radiator 400 and the second antenna radiator 600 in use.

That is, when the first and second antenna floor parts 210 and 220 are folded with each other, the first antenna radiator part between the first preset point 416 and the second end 414 of the first antenna radiator 400 is overlapped with or separated from the second antenna radiator part between the second preset point 616 and the second end 614 of the second antenna radiator 600, and the first antenna radiator part between the first preset point 416 and the first end 412 of the first antenna radiator 400 is separated from the second antenna radiator part between the second preset point 616 and the first end 612 of the second antenna radiator 600 in a direction parallel to the axial direction O2 of the rotation shaft 230.

In this embodiment, the frequency range of the operating frequency band of the first antenna radiator 400 is 700-. The length of the first branch 406 is 10-30mm, and the length of the second branch 606 is 10-30 mm. The capacitance of the first ground capacitor 420 is 1-5pF, and the capacitance of the second ground capacitor is 1-5 pF. It will be appreciated by a person skilled in the art that in alternative other embodiments the operating frequency band of the first antenna radiator 400 and the operating frequency band of the second antenna radiator 600 may also be medium high frequencies.

Further, in the present embodiment, the operating frequency band of the first antenna radiator 400 is the same as the operating frequency band of the second antenna radiator 600. It will be appreciated by a person skilled in the art that in alternative other embodiments the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 may also partly overlap.

In this embodiment, the first grounded capacitor 420 and the second grounded capacitor 620 may be distributed capacitors or lumped capacitors.

In the present embodiment, the first antenna radiator 400 and the second antenna radiator 600 are formed by an outer frame of a middle frame of the foldable electronic device. It will be appreciated by the person skilled in the art that in alternative other embodiments the first antenna radiator 400 and the second antenna radiator 600 may also be formed by patterned metal foils or other metal structures.

As shown in fig. 2 a-2 b, the first antenna radiator 400 is further located near a pair of corners 214 of the first antenna floor portion 210 away from the rotation axis 230 and extends in a bent shape along the corner edges of the pair of corners 214 of the first antenna floor portion 210. And the first antenna radiator 400 has a first straight section 408 and a second straight section 410. The first straight line segment 408 extends along the side edge of the first antenna floor section 210 facing away from the rotation axis 230. First straight segment 408 includes first branch 406. The second straight section 410 is perpendicularly connected to the end of the first straight section 408 of the first antenna radiator 400 distal from the first branch 406.

The second antenna radiator 600 is also located near a pair of corners 224 of the second antenna floor portion 220 away from the rotation axis 230 and extends in a bent shape along corner edges of the pair of corners 224 of the second antenna floor portion 220. And the second antenna radiator 600 also has a first straight segment 608 and a second straight segment 610. The first straight line segment 608 of the second antenna radiator 600 extends along the side edge of the second antenna floor part 220 facing away from the rotation axis 230. The first straight segment 608 of the second antenna radiator 600 includes a second branch 606. The second straight segment 610 of the second antenna radiator 600 is vertically connected to an end of the first straight segment 608 of the second antenna radiator 600 away from the second branch 606.

When the first antenna floor section 210 and the second antenna floor section 220 are spread apart from each other, the diagonal corner 214 of the first antenna floor section 210 away from the rotation axis 230 is disposed opposite the diagonal corner 224 of the second antenna floor section 220 away from the rotation axis 230.

It will be appreciated by those skilled in the art that in alternative embodiments, the first antenna radiator 400 may also extend in a straight line along the side edge of the first antenna floor section 210, and the second antenna radiator 600 may also extend in a straight line along the side edge of the second antenna floor section 220.

In the antenna system 100 of the present application, the pain and difficulty of the existing foldable electronic device antenna design are overcome, and a pair of antennas can be made: when the antenna floor 200 is in the unfolded state, the first antenna radiator 400 and the second antenna radiator 600 may respectively and independently operate, and when the antenna floor 200 is in the folded state, even under the condition that the first antenna radiator 400 and the second antenna radiator 600 are relatively close to each other or even partially overlapped (but not in contact), the first antenna radiator 400 and the second antenna radiator 600 have relatively high isolation and relatively low Envelope Correlation Coefficient (ECC), so that the radiation efficiency and the diversity gain of the antenna are improved, and the first antenna radiator 400 and the second antenna radiator 600 still normally operate, that is, the self-decoupling of the pair of antennas is realized.

As shown in fig. 2a, in the present embodiment, the first antenna radiator 400 and the second antenna radiator 600 are symmetrically disposed with respect to the center of the antenna floor 200. It will be understood by those skilled in the art that the first antenna radiator 400 and the second antenna radiator 600 may also be asymmetrically disposed.

The performance of the antenna system 100 is described in more detail below in conjunction with fig. 3 a-8.

Referring to fig. 3a and fig. 3b, fig. 3a is a graph illustrating simulated S-parameter performance of the first antenna radiator 400 and the second antenna radiator 600 in the operating frequency band when the antenna floor 200 of the antenna system 100 according to an embodiment of the present application is in the two states of the unfolded state and the folded state (i.e., the antenna system 100 corresponding to the two states of fig. 2a and fig. 2 b), where the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 are in the frequency range of 824 MHz and 894 MHz. Fig. 3b is a simulation graph of the performance of the ECC (envelope correlation coefficient) parameters of the first antenna radiator 400 and the second antenna radiator 600 in the operating frequency band measured when the antenna system 100 according to the embodiment of the present application is in the two states of the unfolded state and the folded state of the antenna floor 200 (i.e., the antenna system 100 corresponding to the two states of fig. 2a and fig. 2 b), where the frequency range of the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is 824-894 MHz.

Wherein in fig. 3a the abscissa indicates frequency in GHz and the ordinate indicates amplitude values in dB for S11 and S12. S11, S12 belong to one of the S parameters, respectively. S11 indicates the input reflection coefficient, i.e. the input return loss, which indicates that the first antenna radiator 400 and the second antenna radiator 600 have poor transmission efficiency, and the larger the value, the greater the energy reflected by the first antenna radiator 400 and the second antenna radiator 600, and thus the worse the antenna efficiency. S12 is the reverse transmission coefficient, that is, the greater the amplitude value of S12, the higher the isolation, the higher the radiation efficiency of the first antenna radiator 400 and the second antenna radiator 600.

"S1, 1-fold" in fig. 3a indicates the measured input return loss of the first antenna radiator 400 and the second antenna radiator 600 when the antenna floor 200 is in the folded state (i.e., S11); "S1, 1-deployment" represents the measured input return loss of the first antenna radiator 400 and the second antenna radiator 600 when the antenna floor 200 is in the deployed state (i.e., S11); "S1, 2-fold" denotes the degree of isolation between the first antenna radiator 400 and the second antenna radiator 600 measured when the antenna floor 200 is in the folded state (i.e., S12); "S1, 2-deployment" indicates the degree of isolation between the first antenna radiator 400 and the second antenna radiator 600 measured when the antenna floor 200 is in the deployed state (i.e., S12).

In fig. 3b, the abscissa represents frequency in GHz and the ordinate represents the amplitude value of ECC (envelope correlation coefficient). The smaller the envelope correlation coefficient, the higher the diversity gain of the antenna, the higher the signal-to-noise ratio and the communication quality. "ECC-spread" represents the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 when the antenna floor 200 of the antenna system 100 in fig. 2a is in a spread state. "ECC-folding" represents the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 when the antenna floor 200 of the antenna system 100 in fig. 2b is in a folded state.

The graphs shown in fig. 3a and 3b are obtained by testing the S-parameters and the ECC between the first antenna radiator 400 and the second antenna radiator 600 of the antenna system 100 shown in fig. 2a and 2b by the three-dimensional electromagnetic field simulation software CST.

The simulation conditions under which the graphs shown in fig. 3a and 3b were obtained are shown in table 1 below:

TABLE 1

Since the second antenna 500 and the first antenna 300 are symmetrically arranged and the first branch 406 of the first antenna 300 and the second branch 606 of the second antenna 500 are overlapped, only the relevant parameter values of the first antenna 300 are shown in table 1.

As can be seen from fig. 3a, the isolation (i.e., S12) between the first antenna radiator 400 and the second antenna radiator 600 is still about 15dB at the minimum value in the frequency range 824-894MHz (i.e., 0.824-0.894GHz) of the operating frequency band no matter whether the antenna floor 200 is in the folded state or in the unfolded state, so that the isolation between the first antenna radiator 400 and the second antenna radiator 600 is not seriously deteriorated when the antenna floor 200 is in the folded state, and the first antenna radiator 400 and the second antenna radiator 600 can still operate normally. Wherein the resonance near 1GHz comes from the close-coupled cavity clutter when the antenna floor 200 is in the folded state.

As can be seen from fig. 3b, when the antenna floor 200 is in the unfolded state, the envelope correlation coefficient (i.e., ECC) between the first antenna radiator 400 and the second antenna radiator 600 can be less than 0.1 within the frequency range 824-894MHz (i.e., 0.824-0.894GHz) of the operating frequency band, and when the antenna floor 200 is in the folded state, the envelope correlation coefficient (i.e., ECC) between the first antenna radiator 400 and the second antenna radiator 600 can still be less than 0.2 within the frequency range 824-894MHz (i.e., 0.824-0.894GHz) of the operating frequency band, without serious deterioration, and the first antenna radiator 400 and the second antenna radiator 600 can still operate normally.

It should be noted that, as can be understood by those skilled in the art, when the isolation between the first antenna radiator 400 and the second antenna radiator 600 is greater than 10dB in the frequency range of the operating frequency band, and the envelope correlation coefficient (i.e., ECC) of the first antenna radiator 400 and the second antenna radiator 600 is less than 0.5 in the frequency range of the operating frequency band, the first antenna radiator 400 and the second antenna radiator 600 can operate normally.

To illustrate the operation of the solution claimed in the present application, fig. 4 a-4 c show schematic structural diagrams of three reference designs of the antenna system 100.

Fig. 4a is a schematic structural diagram of the antenna system 100 of the first reference design, in which the first branch 406 (see fig. 2a) and the second branch 606 (see fig. 2a) are removed on the basis of the antenna system 100 (see fig. 2a) of the present application. That is, in the first reference design, the first connection point 404 of the first antenna radiator 400 of the first antenna 300 is connected to the first antenna floor portion 210 of the antenna floor 200 through the first ground capacitor 420, but the first antenna radiator 400 does not have the first stub 406 extending from the first connection point 404 (see fig. 2 a). The second connection point 604 of the second antenna radiator 600 of the second antenna 500 is connected to the second antenna floor part 220 of the antenna floor 200 by means of a second ground capacitor 620, but the second antenna radiator 600 does not have a second branch 606 extending from the second connection point 604 (see fig. 2 a).

Fig. 4b is a schematic structural diagram of the antenna system 100 of the second reference design, in which the first ground capacitor 420 (see fig. 2a) and the second ground capacitor 620 (see fig. 2a) are removed on the basis of the antenna system 100 (see fig. 2a) of the present application, so that the first antenna radiator 400 and the second antenna radiator 600 are directly connected to the antenna floor 200 through a connecting rib. That is, in the second reference design, the first antenna radiator 400 of the first antenna 300 has the first branch 406, but the first antenna radiator 400 is directly connected to the first antenna floor portion 210 of the antenna floor 200 by a tie bar. The second antenna radiator 600 of the second antenna 500 has a second branch 606, but the second antenna radiator 600 is directly connected to the second antenna floor part 220 of the antenna floor 200 by a web.

Fig. 4c is a schematic structural diagram of an antenna system 100 of a third reference design, in which a first branch 406 (see fig. 2a) and a second branch 606 (see fig. 2a) are removed, and a first ground capacitor 420 (see fig. 2a) and a second ground capacitor 620 (see fig. 2a) are removed on the basis of the antenna system 100 (see fig. 2a) of the present application, so that the first antenna radiator 400 and the second antenna radiator 600 are directly connected to the antenna floor 200 through a connecting rib. That is, in the third reference design, the first antenna radiator 400 of the first antenna 300 does not have the first branch 406 (see fig. 2a), and the first antenna radiator 400 is directly connected to the first antenna floor part 210 of the antenna floor 200 by a tie bar. The second antenna radiator 600 of the second antenna does not have a second stub 606 (see fig. 2a), and the second antenna radiator 600 is directly connected to the second antenna floor part 220 of the antenna floor 200 by a web.

Referring to fig. 5 a-5 b, fig. 5a is a graph showing S-parameter performance simulation curves of the first antenna radiator 400 and the second antenna radiator 600 in the operating frequency band, measured when the antenna floor 200 of the antenna system 100 of the present application (i.e., corresponding to the antenna system 100 of fig. 2a and 2 b) and three reference designs (i.e., corresponding to the antenna system 100 shown in fig. 4a, 4b and 4c, respectively) is in a folded state, and the frequency ranges of the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 of the antenna system 100 of the present application and three reference designs are 824-894 MHz.

Fig. 5b is a simulation graph of the performance of the ECC (envelope correlation coefficient) parameters of the first antenna radiator 400 and the second antenna radiator 600 in the operating frequency band measured by the antenna system 100 of the present application (i.e. corresponding to the antenna system 100 of fig. 2a and 2 b) and the three reference designs (i.e. corresponding to the antenna system 100 of fig. 4a, 4b and 4c, respectively) when the antenna floor 200 is in the folded state, and the frequency range of the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 of the antenna system 100 of the present application and the three reference designs is 824-894 MHz. Wherein the content of the first and second substances,

wherein in fig. 5a the abscissa indicates frequency in GHz and the ordinate indicates amplitude values in dB for S11 and S12. S11, S12 belong to one of the S parameters, respectively. S11 indicates the input reflection coefficient, i.e. the input return loss, which indicates that the first antenna radiator 400 and the second antenna radiator 600 have poor transmission efficiency, and the larger the value, the greater the energy reflected by the first antenna radiator 400 and the second antenna radiator 600, and thus the worse the antenna efficiency. S12 is the reverse transmission coefficient, that is, the greater the amplitude value of S12, the higher the isolation, the higher the radiation efficiency of the first antenna radiator 400 and the second antenna radiator 600.

"S1, 1-present application" in fig. 5a indicates the input return loss of the first antenna radiator 400 and the second antenna radiator 600 measured by the antenna system 100 of the present application (i.e., S11); "S1, 1 — reference design 1" denotes the input return loss of the first antenna radiator 400 and the second antenna radiator 600 measured by the antenna system 100 of the first reference design (i.e., S11); "S1, 1-reference design 2" represents the input return loss of the first antenna radiator 400 and the second antenna radiator 600 as measured by the antenna system 100 of the second reference design (i.e., S11); "S1, 1 — reference design 3" indicates the input return loss of the first antenna radiator 400 and the second antenna radiator 600 measured by the antenna system 100 of the third reference design (i.e., S11).

"S1, 2-this application" denotes the degree of isolation between the first antenna radiator 400 and the second antenna radiator 600 as measured by the antenna system 100 of this application (i.e., S12); "S1, 2-reference design 1" denotes the degree of isolation between the first antenna radiator 400 and the second antenna radiator 600 as measured by the antenna system 100 of the first reference design (i.e., S12); "S1, 2-reference design 2" denotes the degree of isolation between the first antenna radiator 400 and the second antenna radiator 600 as measured by the antenna system 100 of the second reference design (i.e., S12); "S1, 2-reference design 3" indicates the degree of isolation between the first antenna radiator 400 and the second antenna radiator 600 (i.e., S12) measured by the antenna system 100 of the third reference design.

In fig. 5b, the abscissa represents frequency in GHz and the ordinate represents the amplitude value of ECC (envelope correlation coefficient). The smaller the envelope correlation coefficient, the higher the diversity gain of the antenna, the higher the signal-to-noise ratio and the communication quality. "ECC-this application" denotes the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 in the antenna system 100 of the present application. "ECC-reference design 1" denotes the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 in the antenna system 100 of the first reference design. "ECC-reference design 2" denotes the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 in the antenna system 100 of the second reference design. "ECC-reference design 3" denotes the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 in the antenna system 100 of the third reference design.

The graphs shown in fig. 5a and 5b are obtained by testing the S-parameters and the ECC between the first antenna radiator 400 and the second antenna radiator 600 of the present application shown in fig. 2a and 2b and the antenna systems 100 of the three reference designs shown in fig. 4 a-4 c when the antenna floor 200 is in the folded state by the three-dimensional electromagnetic field simulation software CST.

The simulation conditions under which the graphs shown in fig. 5a and 5b were obtained are shown in table 2 below:

TABLE 2

Since the second antenna 500 and the first antenna 300 are symmetrically arranged, and the first branch 406 of the first antenna 300 and the second branch 606 of the second antenna 500 are overlapped, only the relevant parameter values of the first antenna 300 are shown in table 2.

As can be seen from fig. 5a, when the antenna floor 200 is in the folded state, in the antenna system 100 proposed in this application and the three reference designs, the isolation (i.e., S12) between the first antenna radiator 400 and the second antenna radiator 600 in the antenna system 100 of this application shown in fig. 2a and fig. 2b is the highest, and the minimum value in the frequency range 824-894MHz of the operating frequency band is still about 15 dB. However, the isolation between the first antenna radiator 400 and the second antenna radiator 600 in the three reference designs shown in fig. 4 a-4 c is low, and the minimum value in the frequency range 824-894MHz of the operating band is only about 10 dB. Wherein the resonance near 1GHz comes from the close-coupled cavity clutter when the antenna floor 200 is in the folded state.

As can be seen from fig. 5b, when the antenna floor 200 is in the folded state, in the antenna system 100 proposed in this application and in the three reference designs, the envelope correlation coefficient (i.e., ECC) between the first antenna radiator 400 and the second antenna radiator 600 in the antenna system 100 of this application shown in fig. 2a and fig. 2b is the lowest, and can reach below 0.2 within the frequency range 824-894MHz of the operating band. However, the envelope correlation coefficient (i.e., ECC) between the first antenna radiator 400 and the second antenna radiator 600 in the three reference designs shown in FIGS. 4 a-4 c is relatively high, up to 0.4-0.5 in the frequency range 824-894MHz of the operating band.

As can be seen from the above, the present application is connected to the first antenna floor part 210 by the first grounded capacitor 420 at a suitable position of the first antenna radiator 400 of the first antenna 300, and the first stub 406 is provided, and at the same time, the second antenna radiator 600 of the second antenna 500 is connected to the second antenna floor part 220 at a suitable position thereof through the second ground capacitor 620, and the second stub 606 is provided such that when the first antenna floor portion 210 and the second antenna floor portion 220 are folded over each other, even in case the first antenna radiator 400 and the second antenna radiator 600 are close to each other or even partly overlap, the first antenna radiator 400 and the second antenna radiator 600 still have a high isolation and a low envelope correlation coefficient (i.e. ECC), so that the first and second antenna radiators 400 and 600 can still normally operate when the antenna floor 200 is in the folded state. That is, the present application can greatly improve the isolation and envelope correlation coefficient (i.e., ECC) of the folded antenna pair relative to the antenna system 100 of the three reference designs.

The operation of the antenna system 100 of the present application is described in detail below with reference to fig. 6a to 8 by taking the first antenna 300 as an example. Those skilled in the art will appreciate that the same analysis means as the first antenna 300 may be employed for the second antenna 500.

Fig. 6a is a partial structural diagram of the antenna system 100 according to an embodiment of the present application, wherein only the first antenna 300 is retained and the antenna floor 200 is in an unfolded state. That is, the figure is based on the antenna system 100 shown in fig. 2a with the second antenna 500 removed.

Fig. 6b is a partial structural diagram of the antenna system 100 of the first reference design, in which only the first antenna 300 is retained and the antenna floor 200 is in an unfolded state. That is, the figure is based on the antenna system 100 shown in fig. 4a with the second antenna 500 removed.

Fig. 6c is a partial structural diagram of the antenna system 100 of the second reference design, in which only the first antenna 300 is retained and the antenna floor 200 is in the unfolded state. That is, the figure is based on the antenna system 100 shown in fig. 4b with the second antenna 500 removed.

Fig. 7 a-7 c are schematic diagrams of current distribution on the antenna floor 200 of the antenna system 100 of the present application, the first reference design and the second reference design of fig. 6 a-6 c at the same operating frequency for the first antenna radiator 400, respectively. Wherein the operating frequency of the first antenna radiator 400 is 870MHz (i.e., 0.87 GHz). The figures only show the current distribution of the first antenna radiator 400 over the first antenna ground plate portion 210. The current distribution schematic diagram is simulated by three-dimensional electromagnetic field simulation software CST.

In fig. 7a to 7c, the direction indicated by the arrow indicates the current flow direction, and the thickness and length of the arrow indicate the magnitude of the current intensity. And different gray scales in the figure represent different current intensities. It should be noted that the current distribution graph simulated by the three-dimensional electromagnetic field simulation software CST is actually a color graph, and different colors represent different current intensities, which cannot be shown in the current graph, that is, the current intensities of different areas with the same gray scale in fig. 7a to 7c are not necessarily the same.

As shown in fig. 7 a-7 c, for the left half of the first antenna floor portion 210, the current intensity gradually decreases in the direction of the arrow, the current intensity is greatest within the solid line box (i.e., near the upper left corner of the first antenna floor portion 210), and the current intensity is least at the bottom of the first antenna floor portion 210.

As can be seen from fig. 7 a-7 c, in the antenna system 100 of both the first and second reference designs, a stronger current flows into the dashed box (i.e. the upper right corner of the first antenna ground plate portion 210), resulting in a lower isolation and a higher Envelope Correlation Coefficient (ECC) between the first antenna radiator 400 and the second antenna radiator 600 in the folded state. For the antenna solution proposed in the present application, the current in the dashed box, i.e. the upper right corner of the first antenna ground plate portion 210, is weaker, thus having a higher isolation and a lower Envelope Correlation Coefficient (ECC) between the first antenna radiator 400 and the second antenna radiator 600 in the folded state.

Additionally, in the antenna system 100 of the present application and both of the referenced designs, the current density is greatest within the solid box (i.e., near the upper left corner of the first antenna floor portion 210). Here, in the antenna system 100 of the present application, the maximum value of the current is 39.43 dB. In the antenna system 100 of the first reference design, the maximum value of the current is 33.64 dB. In the antenna system 100 of the second reference design, the maximum value of the current is 34.69 dB.

To further illustrate the working mechanism of the present application, fig. 8 shows an equivalent current distribution diagram of the first antenna radiator 400 of the antenna system 100 in fig. 6a on the antenna floor.

As can be seen from fig. 8, when the first antenna radiator 400 works normally and the first feed 440 feeds power, the current flows along the first antenna radiator 400 and splits into two paths when reaching the first connection point 404, one path of the current flows along the first ground capacitor 420 to the antenna floor 200, and the other path of the current continues to move to the right along the first antenna radiator 400 on the first branch 406. Here, the current passing through the ground of the first ground capacitor 420 flows to the left and right of the antenna floor 200, the floor current flowing to the left of the antenna floor 200 is denoted by a11, and the floor current flowing to the right of the antenna floor 200 is denoted by a 12. The current moving to the right on the first leg 406, due to electromagnetic field boundary conditions, also causes a current to flow to the left on the antenna floor 200, which is denoted by a 2. When the floor current a12 and the floor current a2 are reversed in equal amplitude, little floor current will flow to the right, i.e. little current will flow to the right of the antenna floor 200, so that a higher isolation and a lower Envelope Correlation Coefficient (ECC) between the first antenna radiator 400 and the second antenna radiator 600 in the folded state can be achieved.

It will be appreciated by those skilled in the art that the working mechanism of the equivalent current distribution of the second antenna radiator 600 on the second antenna floor part 220 is the same as the working mechanism of the equivalent current distribution of the first antenna radiator 400 on the first antenna floor part 210.

That is, in the present application, the current distribution of the first antenna radiator 400 on the first antenna floor part 210 and the current distribution of the second antenna radiator 600 on the second antenna floor part 220 may be specifically such that, referring to fig. 2a, 2b and 8, the first antenna radiator 400 forms a first floor current a11 flowing toward the first direction (i.e., flowing toward the left in fig. 8) and a second floor current a12 flowing toward the second direction (i.e., flowing toward the right in fig. 8) on the first antenna floor part 210 through the current of the first ground capacitor 420, the first direction and the second direction being opposite. The current flowing on the first stub 406 forms a third floor current a2 flowing in the first direction (i.e., toward the left in fig. 8) at the first antenna ground portion 210, with the second floor current a12 and the third floor current a2 having substantially equal magnitudes. The second antenna radiator 600 forms a fourth floor current (not shown) flowing in the first direction (i.e., flowing toward the left in fig. 8) and a fifth floor current (not shown) flowing in the second direction (i.e., flowing toward the right in fig. 8) in the second antenna floor part 220 through the current of the second ground capacitor 620, and the current flowing in the second branch 606 forms a sixth floor current (not shown) flowing in the second direction (i.e., flowing toward the right in fig. 8) in the second antenna floor part 220, and the magnitudes of the fourth floor current and the sixth floor current are substantially equal.

Referring to fig. 9, fig. 9 is a schematic structural diagram of an antenna system 100 according to another embodiment of the present application, wherein an antenna floor 200 is in an unfolded state. As shown in fig. 9, the structure of the antenna system 100 of this embodiment is substantially the same as the structure of the antenna system 100 provided in the above embodiment, except that the first antenna 300 further includes a first switch 700, the first switch 700 is connected between the first antenna radiator 400 and the first antenna floor portion 210, and the first antenna radiator 400 operates in different sub-bands by switching of the first switch 700.

In this embodiment, the portion of the first antenna radiator 400 located between the first antenna feed point and the first end 412 of the first antenna radiator 400 is a first extension, and the first switch 700 is connected between the first extension and the first antenna floor portion 210. It will be appreciated by those skilled in the art that in alternative embodiments, the first switch 700 may be disposed at other suitable locations on the first antenna radiator 400.

Further, the second antenna 500 further includes a second switch 800, the second switch 800 is connected between the second antenna radiator 600 and the second antenna floor part 220, and the second antenna radiator 600 operates in different sub-bands by switching of the second switch 800.

In this embodiment, the second antenna radiator portion located between the second antenna feeding point 602 and the first end 612 of the second antenna radiator 600 is a second extension, and the second switch 800 is connected between the second extension and the second antenna floor part 220. It will be appreciated by those skilled in the art that in alternative embodiments, the second switch 800 may be disposed at other suitable locations on the second antenna radiator 600.

Specifically, the first switch 700 and the second switch 800 both use single-pole multi-throw switches, so that the first switch 700 corresponds to a plurality of sub-bands in which the first antenna radiator 400 operates, and the second switch 800 corresponds to a plurality of sub-bands in which the second antenna radiator 600 operates. In this embodiment, each of the first switch 700 and the second switch 800 is a single-pole four-throw switch. Those skilled in the art will appreciate that in alternative embodiments, multiple pole, multiple throw switches may be used for the first and second switches.

In this embodiment, the first switch 700 and the first antenna radiator 400 are connected to each other through two paths, and the first capacitor 720 is provided on each of the two paths, and the first inductor 740 is provided on each of the other two paths. When the first inductor 740 is tangentially provided to the first switch 700, the operating frequency band of the first antenna radiator 400 is shifted to a high frequency. When the first switch 700 tangentially sets the first capacitor 720, the operating frequency band of the first antenna radiator 400 is shifted to a low frequency.

Also, when the first switch 700 is tangent to the first inductor 740 with different inductance, the operating frequency band of the first antenna radiator 400 is shifted. When the first switch 700 is switched to the first capacitor 720 with different capacitance, the operating frequency band of the first antenna radiator 400 is shifted.

It should be noted that, in use, the positions and the numbers of the first inductor 740 and the first capacitor 720 may be set according to actual needs, and the first inductor 740 with a suitable inductance value and the first capacitor 720 with a suitable capacitance value may also be set.

Two of the two paths of the second switch 800 connected to the second antenna radiator 600 are provided with the second capacitor 820, and the other two paths are provided with the second inductor 840. When the second switch 800 tangentially arranges the second inductor 840, the operating frequency band of the second antenna radiator 600 moves towards high frequencies. When the second switch 800 tangentially arranges the second capacitor 820, the operating frequency band of the second antenna radiator 600 moves towards a low frequency.

Also, when the second switch 800 is tangent to the second inductor 840 having a different inductance value, the operating frequency band of the second antenna radiator 600 is shifted. When the second switch 800 is tangent to the second capacitor 820 with different capacitance, the operating frequency band of the second antenna radiator 600 also moves.

It should be noted that, in use, the positions and the numbers of the second inductor 840 and the second capacitor 820 may be set according to actual needs, and the second inductor 840 with a suitable inductance value and the second capacitor 820 with a suitable capacitance value may also be set.

Further, the plurality of sub-bands in which the first antenna radiator 400 operates and the plurality of sub-bands in which the second antenna radiator 600 operates all include a first sub-band, a second sub-band, a third sub-band, and a fourth sub-band. The frequency range of the first sub-band is 704-788 MHz. The frequency range of the second sub-band is 791-. The frequency range of the third sub-band is 824-894 MHz. The frequency range of the fourth sub-band is 880-960 MHz.

In this embodiment, when the first switch 700 and the second switch 800 respectively cut into one of the first capacitors 720 and one of the second capacitors 820, the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 are switched to the first sub-band. When the first switch 700 and the second switch 800 are respectively directed to the other first capacitor 720 and the other second capacitor 820, the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 are switched to the second sub-band. When the first switch 700 and the second switch 800 are all turned off, the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 are switched to the third sub-band. When the first switch 700 and the second switch 800 are respectively tangent to the first inductor 740 and the second inductor 840, the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 are switched to the fourth sub-band. It will be understood by those skilled in the art that the present disclosure is only exemplary, and the switching manner of the operating band is not limited thereto.

As shown in fig. 9, the first ground capacitor 420 and the second ground capacitor 620 are both adjustable capacitors, and the isolation and the envelope correlation coefficient of the first antenna radiator 400 and the second antenna radiator 600 are adjusted by adjusting the capacitance values of the first ground capacitor 420 and the second ground capacitor 620. When the antenna operates in different frequency bands, the first grounded capacitor 420 and the second grounded capacitor 620 also operate at corresponding capacitance values in order to achieve optimal isolation and Envelope Correlation Coefficient (ECC).

The performance of the antenna system 100 provided in the present embodiment is specifically described below with reference to fig. 10a to 10 b.

Fig. 10a is a graph illustrating S-parameter performance simulation curves of three operating sub-bands of the first antenna radiator 400 and the second antenna radiator 600 measured when the antenna floor 200 of the antenna system 100 (the antenna system 100 shown in fig. 9) according to the present embodiment of the application is in a folded state. Fig. 10b is a graph illustrating the performance of ECC (envelope correlation coefficient) parameters of three sub-bands in which the first antenna radiator 400 and the second antenna radiator 600 operate, which is measured when the antenna system 100 (the antenna system 100 shown in fig. 9) of the present embodiment of the application is in a folded state.

B28 in the figure represents a first sub-band with a frequency range of 704-788 MHz. B5 in the figure represents a third sub-band with a frequency range of 824-894 MHz. B8 in the figure represents the fourth sub-band, which has a frequency range of 880-960 MHz.

It will be understood by those skilled in the art that the frequency range of the second sub-band B20 is 791-.

In fig. 10a, the abscissa indicates frequency in GHz, and the ordinate indicates amplitude values in dB for S11 and S12. S11, S12 belong to one of the S parameters, respectively. S11 represents the input reflection coefficient, i.e., the input return loss. S12 is the reverse transmission coefficient, i.e., the isolation.

"S1, 1-B5" in fig. 10a indicates the measured input return loss (i.e., S11) when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the third sub-band; "S1, 1-B8" represents the input return loss measured when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the fourth sub-band (i.e., S11); "S1, 1-B28" represents the input return loss measured when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the first sub-band (i.e., S11).

"S1, 2-B5" indicates the measured isolation (i.e., S12) when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the third sub-band; "S1, 2-B8" indicates the measured isolation between the first antenna radiator 400 and the second antenna radiator 600 when the operating frequency band is the fourth sub-band (i.e., S12); "S1, 2-B28" indicates the measured isolation (i.e., S12) when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the first sub-band.

In fig. 10b, the abscissa represents frequency in GHz and the ordinate represents the amplitude value of ECC (envelope correlation coefficient). The smaller the envelope correlation coefficient, the higher the diversity gain of the antenna, the higher the signal-to-noise ratio and the communication quality. "ECC-B5" represents the envelope correlation coefficient measured when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the third sub-band. "ECC-B8" represents the envelope correlation coefficient measured when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the fourth sub-band. "ECC-B28" represents the envelope correlation coefficient measured when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the first sub-band.

The graphs shown in fig. 10a and 10b are obtained by testing the S-parameters and ECC between the first antenna radiator 400 and the second antenna radiator 600 of the antenna system 100 shown in fig. 9 in a folded state by the three-dimensional electromagnetic field simulation software CST.

The simulation conditions under which the graphs shown in fig. 10a and 10b were obtained are shown in table 3 below: b28 in the figure represents a first sub-band with a frequency range of 704-788 MHz. B5 in the figure represents a third sub-band with a frequency range of 824-894 MHz. B8 in the figure represents the fourth sub-band, which has a frequency range of 880-960 MHz.

TABLE 3

Since the second antenna 500 and the first antenna 300 are symmetrically arranged and the first branch 406 of the first antenna 300 and the second branch 606 of the second antenna 500 are overlapped, only the relevant parameter values of the first antenna 300 are shown in table 3.

As can be seen from fig. 10a, when the first antenna radiator 400 and the second antenna radiator 600 are switched to different operating frequency bands, the isolation between the first antenna radiator 400 and the second antenna radiator 600 may be changed to a certain extent, but the minimum value is still about 15dB, so that the first antenna radiator 400 and the second antenna radiator 600 can still operate normally when switched to different operating frequency bands in the folded state. Wherein the resonance near 1GHz comes from the close-coupled cavity clutter when the antenna floor 200 is in the folded state.

Specifically, when the operating frequency bands of the first antenna radiator 400 and the second antenna radiator 600 are the first sub-band B28, the minimum value of the isolation between the first antenna radiator 400 and the second antenna radiator 600 in the frequency range 704-788MHz of the operating frequency band is still 16 dB. When the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the third sub-band B5, the isolation between the first antenna radiator 400 and the second antenna radiator 600 is still at the minimum value of 14dB within the frequency range 824-894MHz of the operating frequency band. When the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the fourth sub-band B8, the isolation between the first antenna radiator 400 and the second antenna radiator 600 is still at the minimum value of 13dB within the frequency range 880-960MHz of the operating frequency band.

As can be seen from fig. 10b, when the first antenna radiator 400 and the second antenna radiator 600 are switched to different operating frequency bands, the envelope correlation coefficient (i.e., ECC) between the first antenna radiator 400 and the second antenna radiator 600 is lower than 0.4 in the operating frequency band.

Specifically, when the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the first sub-band B28, the envelope correlation coefficient between the first antenna radiator 400 and the second antenna radiator 600 is lower than 0.2 in the frequency range 704-788MHz of the operating frequency band. When the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the third sub-band B5, the envelope correlation coefficient between the first antenna radiator 400 and the second antenna radiator 600 is lower than 0.2 in the frequency range 824-894MHz of the operating frequency band. When the operating frequency band of the first antenna radiator 400 and the second antenna radiator 600 is the fourth sub-band B8, the envelope correlation coefficient between the first antenna radiator 400 and the second antenna radiator 600 is lower than 0.4 in the frequency range 880-960MHz of the operating frequency band.

In summary, the foldable electronic device of the present application is connected to the first antenna floor part 210 by the first ground capacitor 420 at a suitable position of the first antenna radiator 400 and the first stub 406 is provided, while at the same time, connected to the second antenna floor part 220 by the second ground capacitor 620 at a suitable position of the second antenna radiator 600 and the second stub 606 is provided, so that the antenna pair: when the first antenna floor part 210 and the second antenna floor part 220 are unfolded from each other, the first antenna radiator 400 and the second antenna radiator 600 operate independently; when the first antenna floor part 210 and the second antenna floor part 220 are folded onto each other, even if the first antenna radiator 400 and the second antenna radiator 600 are close to each other or even partially overlap each other (e.g. in case of the first stub 406 and the second stub 606 being partially overlapped), there is still a high degree of isolation and a low coefficient of envelope correlation (i.e. ECC) between the first antenna radiator 400 and the second antenna radiator 600, so that the first antenna radiator 400 and the second antenna radiator 600 can still function normally when the antenna floor 200 is in the folded state, i.e. both antennas still function normally in the folded state, with the same number of antennas operating as in the unfolded state. Moreover, the switch can be switched to work in different frequency bands, so that the performance of similar unfolding states of all the frequency bands in the folding state is realized.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.