阅读说明：本技术 一种极化和方向图复合可重构天线 (Polarization and directional diagram composite reconfigurable antenna ) 是由 李文涛 魏萌 王一鸣 蘧浩天 史小卫 于 2020-05-12 设计创作，主要内容包括：本发明提出了一种极化和方向图复合可重构天线,用于解决现有技术中存在的可重构极化状态少,由于天线单元馈电端口多,导致的馈电系统复杂的技术问题,包括上下层叠的第一介质基板和第二介质基板,其中,在第一介质基板上表面加载有射频开关,包括用于连接十字型金属贴片和矩形贴片的等效射频开关和用于连接不同寄生像素贴片的理想射频开关,通过控制这些射频开关的连通与断开状态,天线可以实现三种极化状态,分别为线极化、左旋圆极化和右旋圆极化,且在每种极化状态下,利用可重构的寄生像素贴片都可使主波束发生偏转,可应用于遥感遥测、无线通讯等领域。(The invention provides a polarization and directional diagram composite reconfigurable antenna, which is used for solving the problems that the reconfigurable polarization state is few in the prior art, the technical problem of complex feeding system caused by a plurality of feeding ports of the antenna unit comprises a first dielectric substrate and a second dielectric substrate which are stacked up and down, wherein, the upper surface of the first dielectric substrate is loaded with a radio frequency switch which comprises an equivalent radio frequency switch used for connecting the cross-shaped metal patch and the rectangular patch and an ideal radio frequency switch used for connecting different parasitic pixel patches, by controlling the on and off states of the RF switches, the antenna can realize three polarization states, namely linear polarization, left-hand circular polarization and right-hand circular polarization, in each polarization state, the main beam can be deflected by using the reconfigurable parasitic pixel patch, and the method can be applied to the fields of remote sensing and remote measuring, wireless communication and the like.)

1. A polarization and directional pattern composite reconfigurable antenna comprises a first dielectric substrate (1) and a second dielectric substrate (2) which are stacked up and down, and is characterized in that:

a driving unit (3) is printed at the central position of the upper surface of the first medium substrate (1), and a plurality of parasitic pixel patches (4) which are periodically arranged are printed at the periphery of the driving unit (3); the driving unit (3) comprises a cross-shaped metal patch (31) and rectangular patches (32) located at the spatial positions of four corners of the cross-shaped metal patch (31), the four rectangular patches (32) are respectively connected with the cross-shaped metal patch (31) through one or more equivalent radio frequency switches (33), each rectangular patch (32) is respectively connected with a first radio frequency choke inductor (34), and the polarization reconfigurable characteristic of the antenna is realized through the control of the connection and disconnection states of the equivalent radio frequency switches (33); the parasitic pixel patches (4) are of a rectangular structure, adjacent parasitic pixel patches (4) are connected through an ideal radio frequency switch (5), and the directional diagram reconfigurable characteristic of the antenna is realized by controlling the connection and disconnection states of the ideal radio frequency switch (5);

the upper surface of the second dielectric substrate (2) is printed with a metal microstrip line (6), and the lower surface is printed with a metal floor (7) and a second radio frequency choke inductor (8) which is positioned at the projection position of the first radio frequency choke inductor (34) on the lower surface of the second dielectric substrate (2);

the first radio frequency choke inductor (34) is connected with one end of a second radio frequency choke inductor (8) on the lower surface of the second dielectric substrate (2) through a metalized through hole, and the other end of the second radio frequency choke inductor (8) is connected with the metal floor (7).

2. A polarization and pattern composite reconfigurable antenna according to claim 1, characterized in that the center of the cross-shaped metal patch (31) is located on the center normal of the first dielectric substrate (1).

3. A polarization and pattern composite reconfigurable antenna according to claim 1, characterized in that the centers of the rectangular patches (32) are located on the diagonal of the cross-shaped metal patch (31), and the four rectangular patches (32) are equidistant from the center of the cross-shaped metal patch (31).

4. A polarization and pattern composite reconfigurable antenna according to claim 1, characterized in that the plurality of parasitic pixel patches (4) arranged periodically form an array of parasitic pixel patches with one parasitic pixel patch (4) being absent at each of the four corners of the array, and the center of the array of parasitic pixel patches coincides with the center of the cross-shaped metal patch (31).

5. A polarization and pattern composite reconfigurable antenna according to claim 1, characterized in that the parasitic pixel patch (4) is rectangular in shape, with a rectangular protrusion provided at the midpoint position of each side.

6. A polarization and pattern composite reconfigurable antenna according to claim 1, characterized in that the equivalent radio frequency switch (33) and the ideal radio frequency switch (5) adopt any one of a micro electro mechanical system switch, a PIN type diode switch and a field effect transistor switch.

7. A polarization and pattern composite reconfigurable antenna according to claim 1, characterized in that the first dielectric substrate (1) and the second dielectric substrate (2) are made of plates with a relative dielectric constant of 2.65.

Technical Field

The invention belongs to the technical field of antennas, and relates to a polarization and directional diagram composite reconfigurable antenna which can be applied to the fields of remote sensing and remote measuring, wireless communication and the like.

Background

With the progress of scientific technology, the demand of people for information has increased unprecedentedly, so that the communication technology is developed dramatically. As an important branch of the communication field, wireless communication gets widely used in various fields such as national defense and civil life because of getting rid of dependence on physical transmission lines. The antenna is an information access port of the radio equipment, and the quality of the antenna performance directly influences the communication quality of the whole wireless communication system.

Nowadays, wireless communication is gradually accelerated to enter an era of multifunction, large capacity and ultra wide band, and the rapid development of modern wireless communication systems directly leads to the increasing number of subsystems on the same platform, and meanwhile, the number of antennas is correspondingly increased. With the increase of the number of antennas on the same platform, the problems of large volume, high cost, electromagnetic compatibility and the like also synchronously occur. In order to solve the problems, a reconfigurable antenna is developed, which can change the characteristics of the antenna such as the working frequency, the radiation pattern and the polarization mode according to the use requirements of different environments, thereby meeting the requirements of a wireless communication system. The frequency reconfigurable antenna can improve the frequency spectrum utilization rate of a communication system; the directional diagram reconfigurable antenna can save the energy of a communication system and improve the safety of the communication system; the polarization reconfigurable antenna can be additionally provided with an additional receiving and transmitting channel, and has great contribution in the aspects of polarization diversity, frequency division multiplexing and the like.

Researchers at home and abroad mainly concentrate on polarization reconfigurable antennas and directional diagram reconfigurable antennas, and put forward various antenna design schemes with independent reconfigurable polarization or directional diagrams. However, the polarization and directional diagram of the antenna can be simultaneously reconstructed, so that the spatial degree of freedom can be improved, the system capacity of the wireless communication system is improved, the problem of polarization mismatch in communication is solved, the electronic interference between systems can be avoided, the frequency spectrum utilization rate is improved, and the transmission rate of the communication system is improved. In addition, in order to obtain the maximum signal amplitude value at the receiving antenna end, different polarization wave transmission needs to be selected by matching a specific polarization mode when high-frequency waves with different frequencies are transmitted, so that the reconfigurable polarization number of the antenna is maximized as much as possible when the polarization reconfigurable antenna is designed. However, some existing antennas with reconfigurable polarization and directional pattern combinations only switch between left-hand circular polarization and right-hand circular polarization or between horizontal polarization and vertical polarization when polarization reconfiguration is implemented, and these antennas are rarely capable of switching between circular polarization and linear polarization.

For example, patent application with application publication number CN108963472A entitled "a directional diagram, polarization reconfigurable antenna" discloses a directional diagram, polarization reconfigurable antenna, which includes four antenna units and four switches corresponding to the antenna units one by one, each antenna unit has two pairs of controllable perturbation portions, the two pairs of controllable perturbation portions are respectively connected with the switches corresponding to the antenna unit where the two pairs of controllable perturbation portions are located, and the switches are used for controlling the states of the perturbation portions so as to change the perturbation on the current; each antenna unit comprises three feeding ports, the feeding ports of the antenna units are respectively connected with the corresponding switches of the antenna units through transmission lines by feeding probes, the transmission lines are divided into two parts through a first equal-phase equal-amplitude power divider, each part is divided into two parts through a second equal-phase equal-amplitude power divider, and the four finally divided parts are respectively connected with four switches. The antenna is of a three-layer structure, the state of a feed port of an antenna unit is changed through the control switch, so that the directional diagram of the antenna array is changed, the two pairs of controllable perturbation parts are switched through the control switch, the perturbation on the current is changed, and the switching of left-hand circular polarization and right-hand circular polarization is realized. Although the antenna realizes the reconfiguration of polarization and a directional diagram, the antenna has the defects that the antenna can only be switched between left-hand circular polarization and right-hand circular polarization states, and in addition, the antenna unit adopts multiple ports, so that a feed system is complex, the design difficulty of the antenna is increased, and therefore, the antenna is limited in practical application to a certain extent.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a polarization and directional pattern composite reconfigurable antenna which is used for solving the technical problems that the reconfigurable polarization state is few, and the feeding system is complex due to the fact that the number of feeding ports of an antenna unit is large in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that:

a polarization and directional pattern composite reconfigurable antenna comprises a first dielectric substrate 1 and a second dielectric substrate 2 which are stacked up and down:

a driving unit 3 is printed at the central position of the upper surface of the first medium substrate 1, and a plurality of parasitic pixel patches 4 which are periodically arranged are printed at the periphery of the driving unit 3; the driving unit 3 comprises a cross-shaped metal patch 31 and rectangular patches 32 positioned at spatial positions of four corners of the cross-shaped metal patch 31, the four rectangular patches 32 are respectively connected with the cross-shaped metal patch 31 through one or more equivalent radio frequency switches 33, each rectangular patch 32 is respectively connected with one radio frequency choke inductor 34, and the polarization reconfigurable characteristic of the antenna is realized through the control of the connection and disconnection states of the equivalent radio frequency switches 33; the parasitic pixel patches 4 are of a rectangular structure, adjacent parasitic pixel patches 4 are connected through an ideal radio frequency switch 5, and the directional diagram reconfigurable characteristic of the antenna is realized by controlling the connection and disconnection states of the ideal radio frequency switch 5;

the upper surface of the second dielectric substrate 2 is printed with a metal microstrip line 6, and the lower surface is printed with a metal floor 7 and a second radio frequency choke inductor 8 positioned at the projection position of the first radio frequency choke inductor 34 on the lower surface of the second dielectric substrate 2;

the first radio frequency choke inductor 34 is connected with one end of a second radio frequency choke inductor 8 on the lower surface of the second dielectric substrate 2 through a metallized via hole, and the other end of the second radio frequency choke inductor 8 is connected with the metal floor 7.

In the polarization and directional pattern composite reconfigurable antenna, the center of the cross-shaped metal patch 31 is located on the central normal of the first dielectric substrate 1.

In the polarization and directional pattern composite reconfigurable antenna, the centers of the rectangular patches 32 are located on the diagonal line of the cross-shaped metal patch 31, and the distances between the four rectangular patches 32 and the center of the cross-shaped metal patch 31 are equal.

In the polarization and directional pattern composite reconfigurable antenna, the positions of four corners of a parasitic pixel patch array formed by the plurality of parasitic pixel patches 4 which are periodically arranged are respectively provided with one parasitic pixel patch 4, and the center of the parasitic pixel patch array is superposed with the center of the cross-shaped metal patch 31.

In the polarization and directional pattern composite reconfigurable antenna, the parasitic pixel patch 4 is rectangular, and a rectangular protrusion is arranged at the midpoint of each side of the parasitic pixel patch.

In the polarization and directional pattern composite reconfigurable antenna, the equivalent radio frequency switch 33 and the ideal radio frequency switch 5 adopt any one of a micro-electromechanical system switch, a PIN diode switch and a field effect transistor switch.

According to the polarization and directional pattern composite reconfigurable antenna, the first dielectric substrate 1 and the second dielectric substrate 2 are made of plates with the relative dielectric constant of 2.65.

Compared with the prior art, the invention has the following advantages:

① the invention can realize the left-hand circular polarization, right-hand circular polarization and linear polarization characteristics of the antenna by controlling the on-off state of the equivalent radio frequency switch loaded between the cross metal patch and the rectangular patch;

② the invention has only one feed port, which avoids the complex feed system problem caused by the multiple feed ports of the antenna unit in the prior art, and makes the invention simple in structure and easy to realize.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a top view of the upper surface of a first dielectric substrate according to the present invention;

FIG. 3 is a schematic structural diagram of a second dielectric substrate according to the present invention;

fig. 4 is a topological structure diagram of the upper surface of the first dielectric substrate corresponding to four deflection angles when the embodiment of the present invention operates in a left-handed circular polarization state;

fig. 5 is a topological structure diagram of the upper surface of the first dielectric substrate corresponding to four deflection angles when the embodiment of the present invention operates in the right-hand circular polarization state;

FIG. 6 is a topological structure diagram of the upper surface of the first dielectric substrate corresponding to three deflection angles when the embodiment of the present invention operates in a linear polarization state;

FIG. 7 is a diagram showing simulation results of reflection coefficient, axial ratio and gain of an antenna operating in three polarization states under the condition that an antenna directional diagram is not deflected according to the embodiment of the present invention;

FIG. 8 is a diagram showing simulation results of reflection coefficients and axial ratios corresponding to four deflection angles when the embodiment of the present invention is operated in a left-handed circular polarization state;

fig. 9 shows the radiation patterns of the plane with four deflection angles phi of 0 ° at a frequency f of 4.72GHz when the embodiment of the present invention is operated in the left-handed circular polarization state;

FIG. 10 is a graph of simulation results of reflection coefficients and axial ratios corresponding to four deflection angles when the embodiment of the present invention operates in a right-hand circular polarization state;

fig. 11 is a radiation pattern of a plane with four deflection angles phi of 0 ° at a frequency f of 4.72GHz when the embodiment of the present invention operates in a right-hand circular polarization state;

FIG. 12 is a diagram showing simulation results of reflection coefficients corresponding to three deflection angles when the embodiment of the present invention is operated in a linear polarization state;

fig. 13 shows the radiation pattern of the plane with three deflection angles phi of 0 ° at a frequency f of 4.72GHz when the embodiment of the present invention operates in the linear polarization state.

Detailed Description

The invention is described in further detail below with reference to the following figures and specific examples:

referring to fig. 1, the present invention includes a first dielectric substrate 1 and a second dielectric substrate 2 stacked up and down, wherein the first dielectric substrate 1 has a thickness of 1mm, a square F4BM material with a dielectric constant of 2.65 and a loss tangent of 0.002 is used, and a side length is 80mm, the second dielectric substrate 2 has a thickness of 1mm, is made of the same material as the first dielectric substrate 1, and has a physical size of 80mm × 86mm, and in consideration of the actual measurement process with the welding of the shaft head, the second dielectric substrate 2 is designed to have a longer long side than the first dielectric substrate 1, and in terms of a coordinate system in the figure, one end of the second dielectric substrate 2 in the x-axis direction is aligned with one end of the first dielectric substrate 1 in the x-axis direction;

a driving unit 3 is printed at the central position of the upper surface of the first dielectric substrate 1, 28 parasitic pixel patches 4 which are periodically arranged are printed at the periphery of the driving unit 3, and the specific structure of the parasitic pixel patches 4 is shown in fig. 2;

the driving unit 3 comprises a cross-shaped metal patch 31 and rectangular patches 32 with the side length w3 being 2.2mm located at the spatial positions of four corners of the cross-shaped metal patch 31, the center of the cross-shaped metal patch 31 is located on the central normal of the first dielectric substrate 1, the center of each rectangular patch 32 is located on the diagonal of the cross-shaped metal patch 31, the four rectangular patches 32 are equidistant from the center of the cross-shaped metal patch 31, the cross-shaped metal patch 31 and the four rectangular patches 32 form a square patch with 4 grooves "L" with the groove width wr 0.8mm and the side length of each groove (2 × w3+2 × wr + l2) being 17.8mm, 4 equivalent radio frequency switches 33 for connecting the cross-shaped metal patch 31 and the rectangular patches 32 are loaded on the opposite corners of the 4 grooves "L", and each rectangular patch 32 is connected with a first radio frequency choke 34 with the inductance value of 100nH, and the polarization control characteristics of the radio frequency choke switches are realized by connecting the 4 equivalent radio frequency chokes 33 in a disconnected state;

in the design process, in order to reduce the using quantity of the ideal radio frequency switch 5 and realize the circular polarization characteristic of the antenna under a larger deflection angle, one parasitic pixel patch 4 is respectively vacant at the positions of four corners of a parasitic pixel patch array formed by the parasitic pixel patches 4 to simulate a cut angle to generate micro-interference, and in addition, the center of the parasitic pixel patch array is superposed with the center of the cross-shaped metal patch 31;

the equivalent radio frequency switch 33 and the ideal radio frequency switch 5 adopt any one of a micro-electromechanical system switch, a PIN type diode switch and a field effect transistor switch, wherein the PIN type diode switch is adopted; the equivalent radio frequency switch 33 simulates the on state of a switch by using a resistor with the resistance value of 3.5 omega, and simulates the off state of a parallel switch by using a resistor with the resistance value of 2.6k omega and a capacitor with the capacitance value of 0.17 pF; an ideal radio frequency switch 5, which is equivalent by a metal sheet;

the upper surface of the second dielectric substrate 2 is printed with a metal microstrip line 6 with a size of 41mm × 1.5.5 mm, the lower surface is printed with a metal floor 7 with a size of 86mm × 80mm and a second radio frequency choke inductor 8 located at the projection position of the first radio frequency choke inductor 34 on the lower surface of the second dielectric substrate 2, the specific structure is shown in fig. 3, wherein the inductance value of the second radio frequency choke inductor 8 is 100 nH;

the first radio frequency choke inductor 34 is connected with one end of a second radio frequency choke inductor 8 on the lower surface of the second dielectric substrate 2 through a metalized via hole, the other end of the second radio frequency choke inductor 8 is connected with the metal floor 7, and the influence of a bias circuit on the radiation performance of the antenna is reduced by arranging the bias circuit on one side of the floor;

and processing the antenna, welding the antenna with a coaxial head, connecting an inner core of the antenna with a metal microstrip line 6 printed on the upper surface of the second dielectric substrate 2, and connecting an outer skin of the antenna with a metal floor 7 printed on the lower surface of the second dielectric substrate 2.

The working principle of the invention is as follows:

according to the invention, a driving unit 3 on the upper surface of a first dielectric substrate is fed in a coupling mode through a metal microstrip line 6, and the polarization reconfigurable state of an antenna is realized by controlling the on-off states of two pairs of equivalent radio frequency switches 33 loaded on opposite angles of an 'L' type groove, wherein referring to a coordinate system in fig. 2, when the equivalent radio frequency switches 33 positioned in a first quadrant and a third quadrant are switched off and the equivalent radio frequency switches 33 positioned in a second quadrant and a fourth quadrant are switched on, the antenna works in a left-handed circular polarization state;

by controlling the on-off of an ideal radio frequency switch 5 connected between different parasitic pixel patches 4, the directional diagram of the antenna in the phi-0-degree plane can be reconstructed. When the antenna works in a left-handed circular polarization state, the radiation characteristic of the antenna is explored by controlling the on-off of the ideal radio frequency switch 5, four switchable directional diagrams are realized on a phi-0-degree plane, and the corresponding topological structures of the upper surface of the first dielectric substrate are respectively shown in fig. 4(a), 4(b), 4(c) and 4 (d); when the antenna works in a right-handed circular polarization state, the radiation characteristic of the antenna is explored by controlling the on-off of the ideal radio frequency switch 5, four switchable directional diagrams are realized on a phi-0-degree plane, and the corresponding topological structures of the upper surface of the first dielectric substrate are respectively shown in fig. 5(a), 5(b), 5(c) and 5 (d); when the antenna works in an on-line polarization state, the radiation characteristics of the antenna are explored by controlling the on-off of the ideal radio frequency switch 5, three switchable directional diagrams are realized on a phi-0-degree plane, and the topological structures of the upper surfaces of the corresponding first dielectric substrates are respectively shown in fig. 6(a), 6(b) and 6 (c).

The effect of the invention can be further explained by combining the simulation result:

1. emulated content

1.1 the reflection coefficient, axial ratio and gain of the antenna operating in three polarization states under the condition that the antenna pattern is not deflected according to the embodiment of the present invention are simulated and calculated by using commercial simulation software HFSS _15.0, and the results are shown in fig. 7(a) and 7 (b).

1.2 the reflection coefficients and axial ratios corresponding to the four deflection angles when the embodiment of the present invention is operated in the left-handed circular polarization state are simulated and calculated by using commercial simulation software HFSS _15.0, and the results are shown in fig. 8(a) and 8 (b).

1.3 the radiation patterns of the plane with four deflection angles phi of 0 ° at a frequency f of 4.72GHz when the embodiment of the present invention is operated in the left-hand circular polarization state are simulated and calculated by using commercial simulation software HFSS _15.0, and the results are shown in fig. 9(a), 9(b), 9(c) and 9 (d).

1.4 the reflection coefficients and axial ratios corresponding to the four deflection angles when the embodiment of the present invention is operated in the right-handed circular polarization state are simulated and calculated by using commercial simulation software HFSS _15.0, and the results are shown in FIGS. 10(a) and 10 (b).

1.5 the radiation patterns of the plane with four deflection angles phi of 0 ° at a frequency f of 4.72GHz, which are operated in the right-hand circular polarization state and are obtained by the simulation calculation of the radiation pattern of the plane with the four deflection angles phi of 0 ° according to the embodiment of the present invention, are implemented by using the commercial simulation software HFSS _15.0, and the results are shown in fig. 11(a), 11(b), 11(c) and 11(d)

1.6, a commercial simulation software HFSS _15.0 is used to perform simulation calculation on reflection coefficients corresponding to three deflection angles when the embodiment of the invention works in a linear polarization state, and the result is shown in fig. 12.

1.7 the radiation patterns of the plane with three deflection angles phi of 0 ° at a frequency f of 4.72GHz in the linear polarization state of the embodiment of the present invention are simulated and calculated by using commercial simulation software HFSS _15.0, and the results are shown in fig. 13(a), 13(b) and 13 (c).

2. Simulation result

Referring to FIG. 7, the reflection coefficients for both the linear and circular polarization states are below-10 dB at around 4.72GHz, and the lateral gains for the left-hand, right-hand, and linear polarization states are approximately 7.02dBi, 7.05dBi, and 6.32dBi, respectively, around this operating frequency. In addition, the axial ratio of the circular polarization state is lower than 3dB at about 4.72 GHz.

Referring to fig. 8, the reflection coefficients of the antennas under the four beam directions are all lower than-10 dB at the working frequency of 4.5GHz to 4.85GHz, and the common bandwidth is 350 MHz. In addition, as can be seen from the figure, the four beams are directed downwards, and the axial ratio of the antenna working at the frequency of 4.72GHz is lower than 3 dB.

Referring to fig. 9, when the deflection is 0 °, the main polarization mode is left-hand circular polarization, the maximum gain is 7.02dBi, and the cross polarization suppression ratio is 20 dB; when the deflection is-21 degrees, the main polarization mode is unchanged, the maximum gain is 6.95dBi, and the cross polarization suppression ratio is 18.9 dB; when the polarization is deflected by 23 degrees, the main polarization mode still remains unchanged, and at the moment, the maximum gain is 6.46dBi, and the cross polarization suppression ratio is 18.4 dB; when the polarization is deflected by 31 degrees, the main polarization mode is still left-hand circular polarization, and the maximum gain is 6.14dBi and the cross polarization suppression ratio is 16.1 dB. Therefore, the consistency of polarization and frequency when the directional diagram is reconfigurable is ensured.

Referring to fig. 10, the reflection coefficients of the antennas under the four beam directions are all lower than-10 dB at the working frequency of 4.5GHz to 4.85GHz, and the common bandwidth is 350 MHz. In addition, as can be seen from the figure, the four beams are directed downwards, and the axial ratio of the antenna working at the frequency of 4.72GHz is lower than 3 dB.

Referring to fig. 11, the main polarization mode of the antenna is right-hand circular polarization at four deflection angles, and when the antenna is deflected by 0 °, the maximum main polarization gain is 7.05dBi, and the cross polarization suppression ratio is 23.7 dB; when the deflection is-16 degrees, the maximum gain of the main polarization is 6.21dBi, and the cross polarization suppression ratio is 21.2 dB; when the deflection is 18 degrees, the maximum gain of the main polarization is 7.47dBi, and the cross polarization suppression ratio is 20.2 dB; when deflected by 31 deg., the main polarization maximum gain is 6.17dBi and the cross polarization suppression ratio is 15.34 dB. Therefore, the consistency of polarization and frequency when the directional diagram is reconfigurable is ensured.

Referring to fig. 12, the reflection coefficients of the antennas under the three beam directions are all lower than-10 dB at the working frequency of 4.64GHz to 4.74GHz, and the common bandwidth is 100 MHz.

Referring to fig. 13, under three deflection angles, the polarization modes of the antenna are all linear polarization, and when the antenna is deflected by 0 °, the maximum main polarization gain is 6.32dBi, and the cross polarization suppression ratio is 54.2 dB; when the deflection is minus 35 degrees, the maximum gain of the main polarization is 8.4dBi, and the cross polarization suppression ratio is 20.3 dB; when deflected 35 °, the main polarization maximum gain was 7.99dBi and the cross polarization suppression ratio was 14.1 dB. Therefore, the consistency of polarization and frequency when the directional diagram is reconfigurable is ensured.

While the invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.