阅读说明：本技术 一种全极化可重构mimo天线 (Full-polarization reconfigurable MIMO antenna ) 是由 韩丽萍 刘宇峰 平艺伟 陈新伟 马润波 张文梅 于 2019-09-29 设计创作，主要内容包括：一种全极化可重构MIMO天线,属于通信系统的天线技术领域,主要解决无线通信系统信道容量低的技术难题。它由两个并排放置的天线单元构成,天线单元包括从上到下依次层叠的辐射贴片、第一介质基板、接地板、第二介质基板以及微带馈线；所述辐射贴片位于第一介质基板的上面,辐射贴片四个角分别刻蚀倾斜缝隙,接地板设置十字缝隙,每条缝隙中加载一个PIN二极管；通过控制辐射贴片的PIN二极管的导通或断开使得天线产生左旋和右旋圆极化工作模式；通过控制接地板的PIN二极管的导通或断开使得天线产生线极化工作模式和圆极化工作模式。本发明可用于增加MIMO通信系统的信道容量,结构简单,成本低、可靠性好。(A full-polarization reconfigurable MIMO antenna belongs to the technical field of antennas of communication systems and mainly solves the technical problem of low channel capacity of a wireless communication system. The antenna unit comprises a radiation patch, a first dielectric substrate, a ground plate, a second dielectric substrate and a microstrip feeder line which are sequentially stacked from top to bottom; the radiation patch is positioned on the first medium substrate, four corners of the radiation patch are respectively etched with inclined gaps, the ground plate is provided with cross gaps, and each gap is loaded with a PIN diode; the antenna generates left-hand and right-hand circular polarization working modes by controlling the connection or disconnection of the PIN diode of the radiation patch; the antenna generates a linear polarization working mode and a circular polarization working mode by controlling the connection or disconnection of the PIN diode of the grounding plate. The invention can be used for increasing the channel capacity of the MIMO communication system, and has the advantages of simple structure, low cost and good reliability.)

1. A fully-polarized reconfigurable MIMO antenna, characterized by: the antenna comprises two antenna units (1) which are arranged side by side, wherein each antenna unit (1) comprises a radiation patch (2), a first dielectric substrate (3), a ground plate (4), a second dielectric substrate (5) and a microstrip feeder line (6) which are sequentially stacked from top to bottom; inclined gaps (7) are etched in four corners of the radiation patch (2), and a PIN diode is loaded in each inclined gap (7); a cross-shaped gap (9) is etched in the center of the grounding plate (4), and four branches of the cross-shaped gap (9) are loaded with a PIN diode respectively; the two grounding plates (4) of the two antenna units are connected into a flat plate, and the two second dielectric substrates (5) of the two antenna units are connected into a flat plate.

2. The fully polarized reconfigurable MIMO antenna according to claim 1, wherein the shape of the radiating patch (2) is a square with a side length of 44mm, the inclined slot (7) is 12mm away from the vertex of the square in both the horizontal and vertical directions of the radiating patch (2), and the width of the inclined slot (7) is 1 mm; the four PIN diodes are loaded in the middle of the inclined gap (7) respectively, and the two diodes on the diagonal line of the radiation patch (2) are simultaneously switched off or switched on.

3. The fully-polarized reconfigurable MIMO antenna according to claim 1, characterized in that the ground plates (4) have dimensions of 75 mm' 75mm, the ground plates (4) of two antenna elements (1) being joined to form a rectangular plate; the cross-shaped gap (9) is positioned at the center of the grounding plate (4), and the length L and the width M of two long gaps forming the cross-shaped gap (9) are respectively 20mm and 2 mm; four branches of the cross-shaped gap (9) D are loaded with one PIN diode, each PIN diode is 2mm away from the center of the cross-shaped gap (9), and the two diodes positioned in the same long gap are simultaneously switched off or switched on.

4. The fully polarized reconfigurable MIMO antenna according to claim 1, characterized in that the first dielectric substrate (3) is a 50mm x 50mm square substrate, using FR4 epoxy material with a dielectric constant of 4.4 and a thickness of 0.8 mm.

5. The fully polarized reconfigurable MIMO antenna according to claim 1, characterized in that the second dielectric substrate (5) is a sheet of FR4 epoxy material with a dielectric constant of 4.4 of 75mm x 75mm and a thickness of 1.6 mm.

6. The fully polarized reconfigurable MIMO antenna according to claim 1, wherein the microstrip feed lines (6) have a length and a width of 43mm and 2.98mm, respectively, and the two feed lines (6) are axisymmetric with respect to a center line of the second dielectric substrate (5) and are spaced 32mm from an upper edge of the second dielectric substrate (5).

7. The full-polarization reconfigurable MIMO antenna according to claim 1, wherein the antenna generates a circular polarization operating mode by controlling the four PIN diodes of the ground plate to be simultaneously turned off, and the two PIN diodes on one long slot of the ground plate are controlled to be simultaneously turned on or off to generate +45 ° linear polarization and-45 ° linear polarization operating modes; the two PIN diodes on the diagonal line of the radiation patch are controlled to be switched on simultaneously, and the antenna is switched off to generate a left-hand circular polarization or right-hand circular polarization working mode.

8. The fully-polarized reconfigurable MIMO antenna according to claim 1, wherein the antenna generates a circular polarization operating mode by controlling the four PIN diodes to be turned off simultaneously, and the two PIN diodes on one long slot of the ground plate are controlled to be turned on or turned off simultaneously so that the antenna generates +45 ° linear polarization and-45 ° linear polarization operating modes; the two PIN diodes on the diagonal line of the radiation patch are controlled to be switched on at the same time, and the antenna is switched off to generate a left-hand circular polarization or right-hand circular polarization working mode.

9. The full-polarization reconfigurable MIMO antenna according to claim 1, wherein in a case where the fifth PIN diode (10-1), the sixth PIN diode (10-2), the seventh PIN diode (10-3) and the eighth PIN diode (10-4) are simultaneously turned off, the antenna operates in a circular polarization mode, when the first PIN diode (8-1) and the third PIN diode (8-3) are simultaneously turned off and the second PIN diode (8-2) and the fourth PIN diode (8-4) are simultaneously turned on, a cut angle in a direction of-45 ° on the patch generates a perturbation to the antenna, and the antenna operates in a left-handed circular polarization mode; when the first PIN diode (8-1) and the third PIN diode (8-3) are simultaneously conducted and the second PIN diode (8-2) and the fourth PIN diode (8-4) are simultaneously disconnected, a tangent angle in the direction of +45 degrees on the patch generates perturbation on the antenna, and the antenna works in a right-handed circular polarization mode.

10. The fully polarized reconfigurable MIMO antenna according to claim 1, wherein in a case where the first PIN diode (8-1), the second PIN diode (8-2), the third PIN diode (8-3) and the fourth PIN diode (8-4) are simultaneously turned on, the antenna operates in a linear polarization mode, when the fifth PIN diode (10-1) and the seventh PIN diode (10-3) are simultaneously turned off and the sixth PIN diode (10-2) and the eighth PIN diode (10-4) are simultaneously turned on, electromagnetic energy is coupled to the patch through a slit in a-45 ° direction on the ground plane, and the antenna operates in a +45 ° linear polarization mode; and when the fifth PIN diode (10-1) and the seventh PIN diode (10-3) are simultaneously conducted and the sixth PIN diode (10-2) and the eighth PIN diode (10-4) are simultaneously disconnected, electromagnetic energy is coupled to the patch through a gap in the + 45-degree direction on the ground plate, and the antenna works in a-45-degree linear polarization mode.

Technical Field

The invention relates to the technical field of antennas in the comprehensive design of a communication system, in particular to a full-polarization reconfigurable MIMO antenna.

Background

With the rapid development of wireless communication technology, spectrum resources are increasingly in short supply, and the demands of users on communication rate and communication quality are increasing, so that a multiple-input multiple-output (MIMO) communication system is in operation. In the MIMO system, a plurality of antenna units are arranged at a signal transmitting end and a signal receiving end, and parallel transmission channels are built in space, so that the frequency spectrum utilization efficiency can be greatly improved. The polarization reconfigurable antenna changes the polarization mode of the antenna according to the use requirements of different environments, and additional receiving and transmitting channels are added. The polarization reconfigurable antenna is applied to the MIMO system, can reduce the correlation among system sub-channels through polarization diversity, and improves the channel capacity of the system. The full-polarization reconfigurable antenna can be freely switched between two orthogonal linear polarizations and two orthogonal circular polarizations, and can select an optimal signal in real time, so that the system performance is greatly improved.

Scholars at home and abroad propose several design schemes of the full-polarization reconfigurable antenna, and the full-polarization reconfigurable antenna is realized by utilizing the reconfigurable feed network. They have the common disadvantage that the use of a feed network increases the complexity of the antenna structure. In addition, these fully polarized reconfigurable antennas are designed for single antenna systems and are not suitable for MIMO systems. How to design a fully-polarized reconfigurable MIMO antenna with a simple structure is a technical problem to be solved, and reports of the fully-polarized reconfigurable MIMO antenna are not seen at present. Therefore, the research on the fully-polarized reconfigurable MIMO antenna is an effective way for solving the technical problem of low channel capacity of a wireless communication system.

Disclosure of Invention

The invention aims to solve the technical problem of low channel capacity of an MIMO communication system, further solve the problem of complex structure of the conventional fully-polarized reconfigurable antenna, and provide a fully-polarized reconfigurable MIMO antenna.

The invention is realized by adopting the following technical scheme: a full-polarization reconfigurable MIMO antenna is composed of two antenna units which are arranged side by side, wherein each antenna unit comprises a radiation patch, a first dielectric substrate, a ground plate, a second dielectric substrate and a microstrip feeder which are sequentially stacked from top to bottom; four corners of the radiation patch are respectively etched with an inclined gap penetrating through the patch, and four PIN diodes are respectively loaded on the four inclined gaps; a cross-shaped gap is etched in the center of the grounding plate, and four PIN diodes are loaded on four branches of the gap respectively; the microstrip feeder line is axisymmetrical with a central line of the second dielectric substrate.

The antenna generates a circular polarization working mode by controlling the four PIN diodes on the grounding plate to be switched off at the same time, and the two PIN diodes on a gap of the grounding plate to be switched on or switched off at the same time so as to generate + 45-degree linear polarization and-45-degree linear polarization working modes; the antenna can generate left-hand circular polarization and right-hand circular polarization working modes by controlling two PIN diodes on the diagonal line of the radiation patch to be switched on or switched off simultaneously.

The four branches of the cross-shaped gap of the grounding plate are respectively loaded with a PIN diode (a fifth PIN diode 10-1, a sixth PIN diode 10-2, a seventh PIN diode 10-3 and an eighth PIN diode 10-4), the four PIN diodes are controlled to be switched off simultaneously to enable the antenna to generate a circular polarization working mode, and the two PIN diodes (10-1, 10-3 or 10-2, 10-4) on the gap of the grounding plate are controlled to be switched on or switched off simultaneously to enable the antenna to generate + 45-degree linear polarization and-45-degree linear polarization working modes;

the inclined gaps of the radiation patch are respectively loaded with a PIN diode (a first PIN diode 8-1, a second PIN diode 8-2, a third PIN diode 8-3 and a fourth PIN diode 8-4), and the two PIN diodes (8-1, 8-3 or 8-2, 8-4) on the diagonal line of the radiation patch are controlled to be switched on or switched off simultaneously, so that the antenna generates left-hand circular polarization and right-hand circular polarization working modes.

Under the condition that the fifth PIN diode 10-1, the sixth PIN diode 10-2, the seventh PIN diode 10-3 and the eighth PIN diode 10-4 are simultaneously disconnected, the antenna works in a circular polarization mode, when the first PIN diode 8-1 and the third PIN diode 8-3 are simultaneously disconnected, and the second PIN diode 8-2 and the fourth PIN diode 8-4 are simultaneously switched on (mode 1), a cutting angle in a direction of-45 degrees on the patch generates micro-interference on the antenna, and the antenna works in a left-hand circular polarization mode; when the first PIN diode 8-1 and the third PIN diode 8-3 are simultaneously conducted and the second PIN diode 8-2 and the fourth PIN diode 8-4 are simultaneously disconnected (mode 2), a tangential angle in a + 45-degree direction on the patch generates perturbation on the antenna, and the antenna works in a right-handed circular polarization mode.

Under the condition that a first PIN diode 8-1, a second PIN diode 8-2, a third PIN diode 8-3 and a fourth PIN diode 8-4 are simultaneously conducted, the antenna works in a linear polarization mode, when a fifth PIN diode 10-1 and a seventh PIN diode 10-3 are simultaneously disconnected and a sixth PIN diode 10-2 and an eighth PIN diode 10-4 are simultaneously conducted (mode 3), electromagnetic energy is coupled to a patch through a gap in the-45-degree direction on a ground plate, and the antenna works in a + 45-degree linear polarization mode (mode 3); when the fifth PIN diode 10-1 and the seventh PIN diode 10-3 are turned on simultaneously and the sixth PIN diode 10-2 and the eighth PIN diode 10-4 are turned off simultaneously (mode 4), electromagnetic energy is coupled to the patch through a gap in the +45 ° direction on the ground plate, and the antenna operates in a-45 ° linear polarization mode.

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

(1) the full-polarization reconfigurable antenna is realized by directly loading a switch on the antenna structure, so that the complexity of the full-polarization reconfigurable antenna is reduced;

(2) the +45 DEG/45 DEG linear polarization working mode and the circular polarization working mode are realized by controlling the diode on the grounding plate, and the left-hand circular polarization working mode and the right-hand circular polarization working mode are further realized by controlling the diode on the radiation patch;

(3) the invention can be switched between four radiation modes of +45 degree \ -45 degree linear polarization mode and left-handed/right-handed circular polarization at will, the antenna has simple structure, low cost and good reliability, and provides an effective solution for high channel capacity of an MIMO communication system.

Drawings

Fig. 1 is a side view of a fully polarized reconfigurable MIMO antenna according to the present invention.

Fig. 2 is a patch plan view of the fully-polarized reconfigurable MIMO antenna unit according to the present invention.

Fig. 3 is a schematic plan view of a ground plate and a feeder line of the fully-polarized reconfigurable MIMO antenna unit according to the present invention.

Fig. 4 is an S-parameter curve of the fully-polarized reconfigurable MIMO antenna mode 1 according to the present invention.

Fig. 5 is an axial ratio curve of the fully-polarized reconfigurable MIMO antenna mode 1 according to the present invention.

Fig. 6 is an S-parameter curve of the fully-polarized reconfigurable MIMO antenna mode 2 according to the present invention.

Fig. 7 is an axial ratio curve of the fully-polarized reconfigurable MIMO antenna mode 2 according to the present invention.

Fig. 8 is an S-parameter curve of the fully-polarized reconfigurable MIMO antenna mode 3 according to the present invention. Fig. 9 is an S-parameter curve of the fully-polarized reconfigurable MIMO antenna mode 4 according to the present invention. Fig. 10 is a radiation pattern of the fully-polarized reconfigurable MIMO antenna mode 1 according to the present invention.

Fig. 11 is a radiation pattern of the fully-polarized reconfigurable MIMO antenna mode 2 according to the present invention. Fig. 12 is a radiation pattern of the fully-polarized reconfigurable MIMO antenna mode 3 according to the present invention.

Fig. 13 is a radiation pattern of the fully-polarized reconfigurable MIMO antenna mode 4 according to the present invention.

In the figure, 1 is an antenna unit, 2 is a patch of the antenna unit, 3 is a first dielectric substrate of the antenna unit, 4 is a ground plate of the antenna unit, 5 is a second dielectric substrate of the antenna unit, 6 is a feeder of the antenna unit, 7 is an inclined slot, 8-1 is a first PIN diode, 8-2 is a second PIN diode, 8-3 is a third PIN diode, 8-4 is a fourth PIN diode, 9 is a cross slot, 10-1 is a fifth PIN diode, 10-2 is a sixth PIN diode, 10-3 is a seventh PIN diode, and 10-4 is an eighth PIN diode.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1, the fully-polarized reconfigurable MIMO antenna is composed of two antenna units 1 placed side by side, where each antenna unit 1 includes a radiation patch 2, a first dielectric substrate 3, a ground plate 4, a second dielectric substrate 5, and a microstrip feeder 6, which are stacked in sequence from top to bottom.

As shown in fig. 2, an inclined gap 7 penetrating through the patch is etched at each of four corners of the radiation patch 2, and the first PIN diode 8-1, the second PIN diode 8-2, the third PIN diode 8-3 and the fourth PIN diode 8-4 are loaded on the four inclined gaps respectively.

As shown in fig. 3, a cross-shaped gap 9 is etched in the middle of the grounding plate 4, and a fifth PIN diode 10-1, a sixth PIN diode 10-2, a seventh PIN diode 10-3 and an eighth PIN diode 10-4 are respectively loaded on four branches of the cross-shaped gap; the microstrip feed line 6 is axisymmetrical with a center line of the second dielectric substrate.

The distance between the inclined gap 7 and the vertex of the square radiation patch 2 along the horizontal direction and the vertical direction of the edge of the radiation patch 2 is 12mm, and the width of the inclined gap 7 is 1 mm; four PIN diodes 8-1, 8-2, 8-3 and 8-4 are loaded at the middle positions of the inclined slits 7, respectively.

The cross-shaped gap 9 is positioned at the center of the grounding plate 4, and the length L and the width M of the cross-shaped gap are respectively 20mm and 2 mm; the four PIN diodes 10-1, 10-2, 10-3 and 10-4 are respectively loaded on the four branches of the gap and are 2mm away from the symmetric center of the gap.

The first dielectric substrate 3 and the second dielectric substrate 5 are both made of FR4 epoxy resin material with the dielectric constant of 4.4, the first dielectric substrate 3 is 50mm multiplied by 50mm in size and 0.8mm in thickness, and the second dielectric substrate 5 is 75mm multiplied by 75mm in size and 1.6mm in thickness.

The microstrip feeder 6 is axisymmetrical with a center line of the second dielectric substrate 5, is 32mm away from the upper edge of the second dielectric substrate 5, and has a length and a width of 43mm and 2.98mm, respectively.

The advantages of the invention can be further illustrated by the simulation results of the embodiments. Modeling simulation is carried out on the full-polarization reconfigurable MIMO antenna in the embodiment of the invention, and a + 45/45 linear polarization and circular polarization working mode is realized by controlling a diode on a grounding plate. And under the condition of the circular polarization mode, the left-hand circular polarization working mode and the right-hand circular polarization working mode are realized by further controlling the diodes on the radiation patches.

Fig. 4 shows the S-parameter curve of a fully polarized reconfigurable MIMO antenna with the second PIN diode 8-2 and the fourth PIN diode 8-4 conducting and the other diodes all off, where the abscissa represents the frequency variation in GHz and the ordinate represents the amplitude variation in dB, it can be seen from the figure that when the antenna is operating in mode 1 (8-2 and 8-4 conducting, 8-1, 8-3, 10-1, 10-2, 10-3 and 10-4 off), the operating centre frequency of the antenna is 2.45GHz, the return loss is lower than-10 dB in the 2.3 ~ 2.7GHz range, and the isolation between the ports is greater than 25.6dB, fig. 5 shows the axial ratio curve of a fully polarized reconfigurable MIMO antenna in mode 1, where the abscissa represents the frequency variation and the ordinate represents the amplitude variation, and the unit is dB, it can be seen from the figure that the axial ratio is less than 3dB in the 2.4 ~ 2.47.47 GHz range.

FIG. 6 shows the S-parameter curve of the fully-polarized reconfigurable MIMO antenna when the first PIN diode 8-1 and the third PIN diode 8-3 are turned on and the other diodes are turned off, and it can be seen from the figure that when the antenna operates in the mode 2 (8-1 and 8-3 are turned on, 8-2, 8-4, 10-1, 10-2, 10-3 and 10-4 are turned off), the operating center frequency of the antenna is 2.45GHz, the return loss is lower than-10 dB in the range of 2.3 ~ 2.7.7 GHz, and the isolation between ports is greater than 25.6 dB. FIG. 7 shows the axial ratio curve of the fully-polarized reconfigurable MIMO antenna in the mode 2, and it can be seen that the axial ratio is less than 3dB in the range of 2.4 ~ 2.46.46 GHz.

As can be seen from the figure, when the antenna works in the mode 3 (the 10-2 and the 10-4 are conducted, and the 8-1, the 8-2, the 8-3, the 8-4, the 10-1 and the 10-3 are disconnected), the working center frequency of the antenna is 2.45GHz, the return loss is lower than-10 dB in the range of 2.4 ~ 2.5.5 GHz, and the isolation between ports is larger than 27.3 dB.

FIG. 9 shows the S-parameter curve of the fully-polarized reconfigurable MIMO antenna when the fifth PIN diode 10-1 and the seventh PIN diode 10-3 are on and the other diodes are off, and it can be seen from the figure that when the antenna operates in mode 4 (10-1 and 10-3 are on, 8-1, 8-2, 8-3, 8-4, 10-2 and 10-4 are off), the operating center frequency of the antenna is 2.45GHz and within the range of 2.4 ~ 2.5.5 GHzS ₁₁|<-10dB, the isolation between ports is greater than 27.2 dB.

Fig. 10 and 11 show the radiation patterns of the fully polarized reconfigurable MIMO antenna in modes 1 and 2, respectively. As can be seen, when the fifth PIN diode 10-1, the sixth PIN diode 10-2, the seventh PIN diode 10-3 and the eighth PIN diode 10-4 are simultaneously turned off, the antenna operates in a circular polarization mode. When the first PIN diode 8-1 and the third PIN diode 8-3 are simultaneously disconnected and the second PIN diode 8-2 and the fourth PIN diode 8-4 are simultaneously connected (mode 1), a cutting angle in a-45-degree direction on the patch generates perturbation on the antenna, and the antenna works in a left-handed circular polarization mode; when the first PIN diode 8-1 and the third PIN diode 8-3 are simultaneously conducted and the second PIN diode 8-2 and the fourth PIN diode 8-4 are simultaneously disconnected (mode 2), a tangential angle of +45 degrees on the patch generates perturbation on the antenna, and the antenna works in a right-handed circular polarization mode.

Fig. 12 and 13 show the radiation patterns of the fully polarized reconfigurable MIMO antenna in modes 3 and 4, respectively. As can be seen from the figure, the antenna operates in a linear polarization mode in the case where the first PIN diode 8-1, the second PIN diode 8-2, the third PIN diode 8-3, and the fourth PIN diode 8-4 are simultaneously turned on. When the fifth PIN diode 10-1 and the seventh PIN diode 10-3 are turned off simultaneously and the sixth PIN diode 10-2 and the eighth PIN diode 10-4 are turned on simultaneously (mode 3), electromagnetic energy is coupled to the patch through a-45-degree-direction gap on the ground plate, and the antenna operates in a + 45-degree linear polarization mode; when the fifth PIN diode 10-1 and the seventh PIN diode 10-3 are turned on simultaneously and the sixth PIN diode 10-2 and the eighth PIN diode 10-4 are turned off simultaneously (mode 4), electromagnetic energy is coupled to the patch through a gap in the +45 ° direction on the ground plate, and the antenna operates in a-45 ° linear polarization mode.