A polarization reconfigurable Fabry-Perot cavity antenna

Abstract

The present invention discloses a polarization reconfigurable Fabry-Perot resonant cavity antenna, comprising a partially reflective cover plate, a patch antenna, a second dielectric plate, a metal floor and a third dielectric plate arranged in sequence from top to bottom, the partially reflective cover plate comprising a first dielectric plate, the upper surface of the first dielectric plate being provided with a plurality of evenly spaced square metal patches, the lower surface of the first dielectric plate being provided with a cross-shaped metal patch corresponding to each square metal patch, the partially reflective cover plate and the metal floor forming a Fabry-Perot resonant cavity, and the lower surface of the third dielectric plate being provided with a polarization reconfigurable feeding network. The polarization reconfigurable Fabry-Perot resonant cavity antenna of the present invention is provided by arranging a patch antenna in a Fabry-Perot resonant cavity formed by a partially reflective cover plate and a metal floor, and arranging a polarization reconfigurable feeding network on the lower surface of the third dielectric plate below the metal floor, so that the antenna can radiate waves of different polarizations, thereby reducing the number of antennas carried on a wireless communication system platform.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to a polarization reconfigurable Fabry-Perot resonant cavity antenna. Background Art

[0002] At present, with the rapid development of electronic technology and communication systems, electronic equipment shows a development trend of ultra-wideband, large capacity and multi-function. Due to the interference of inhomogeneous media and complex environment, the radiated electromagnetic waves may be of any polarization mode. Most traditional antennas can only radiate in a single polarization direction. In order to avoid polarization mismatch, antennas with different polarization modes are added to the wireless communication system platform, resulting in a sharp increase in the number of antennas. However, the coexistence of multiple antennas has brought huge challenges to the electromagnetic compatibility of the wireless communication system platform, and has also led to an increase in the weight and cost of the wireless communication system platform, which has restricted the rapid development and application of wireless communications. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a polarization reconfigurable Fabry-Perot cavity antenna, which can perform polarization reconfiguration to achieve polarization mode switching and reduce the number of antennas mounted on a wireless communication system platform.

[0004] To solve the above technical problems, the objective of the present invention is achieved through the following technical solutions: providing a polarization reconfigurable Fabry-Perot resonant cavity antenna, comprising a partially reflective cover plate, a patch antenna, a second dielectric plate, a metal floor and a third dielectric plate arranged in parallel from top to bottom, the partially reflective cover plate comprising a first dielectric plate, the upper surface of the first dielectric plate is provided with a plurality of evenly spaced square metal patches, the lower surface of the first dielectric plate is provided with a cross-shaped metal patch corresponding to each of the square metal patches, the partially reflective cover plate and the metal floor constitute a Fabry-Perot resonant cavity, and the lower surface of the third dielectric plate is provided with a polarization reconfigurable feeding network.

[0005] A further technical solution is as follows: the cross-shaped metal patch includes a first strip-shaped metal patch and a second strip-shaped metal patch, the first strip-shaped metal patch and the second strip-shaped metal patch have the same size and are stacked vertically to each other.

[0006] Its further technical solution is: the partially reflective cover plate is divided into multiple partially reflective units by the square metal patch, each of the partially reflective units includes a cross-shaped metal patch, a square area of ​​the first dielectric plate corresponding to the cross-shaped metal patch above the cross-shaped metal patch, and the square metal patch corresponding to the cross-shaped metal patch, the width of the first strip metal patch and the second strip metal patch are both 6 mm, the side length of the square metal patch is 17.5 mm, and the side length of the partial reflective unit is 20 mm.

[0007] A further technical solution is as follows: a group of diagonal edges of the patch antenna are respectively formed with cut corners, and a group of opposite side edges of the patch antenna are respectively extended outwards to form branches at midpoints.

[0008] A further technical solution is as follows: the metal floor is provided with four H-shaped gaps around the center, the H-shaped gaps include a first gap and second gaps respectively provided at both ends of the first gap, and the second gaps are vertically connected to the first gaps.

[0009] The further technical scheme is as follows: the polarization reconfigurable feeding network includes a feeding port, a one-to-two Wilkinson power divider, a first 90° phase shifter, a second 90° phase shifter, a first E-type feeder, a second U-type feeder, a first PIN diode, a second PIN diode, a third PIN diode, a fourth PIN diode, a fifth PIN diode, a sixth PIN diode, a seventh PIN diode and an eighth PIN diode, the input branch of the one-to-two Wilkinson power divider is connected to the feeding port, an isolation resistor is connected between the two output branches of the one-to-two Wilkinson power divider, wherein one of the output branches is respectively connected to one end of the first PIN diode and the third P The output branch is connected to one end of the first PIN diode, the other end of the first PIN diode is connected to the first 90° phase shifter and the second PIN diode in sequence, and then connected to the second U-shaped feeder, and the other end of the third PIN diode is connected to the second U-shaped feeder via the fourth PIN diode; the other output branch is respectively connected to one end of the fifth PIN diode and one end of the seventh PIN diode, the other end of the fifth PIN diode is connected to the first E-type feeder via the sixth PIN diode, and the other end of the seventh PIN diode is connected to the second 90° phase shifter and the eighth PIN diode in sequence, and then connected to the first E-type feeder.

[0010] Its further technical solution is: the first E-type feeder includes a first microstrip feeder, two second microstrip feeders arranged on both sides of the end of the first microstrip feeder and connected to the first microstrip feeder, and two third microstrip feeders respectively connected to the second microstrip feeders, the first microstrip feeder is the input feeder of the first E-type feeder, and the sixth PIN diode and the eighth PIN diode are both connected to the first microstrip feeder.

[0011] Its further technical solution is: the second U-shaped feeder includes a fourth microstrip feeder, a circular arc feeder, two fifth microstrip feeders and two sixth microstrip feeders, the fourth microstrip feeder is connected to the middle part of the circular arc feeder, the two ends of the circular arc feeder are respectively connected to one of the fifth microstrip feeders, the sixth microstrip feeder is connected to the fifth microstrip feeder, the fourth microstrip feeder is the input feeder of the second U-shaped feeder, and the second PIN diode and the fourth PIN diode are both connected to the fourth microstrip feeder.

[0012] A further technical solution is that the square metal patches are distributed in a 7×7 matrix on the upper surface of the first dielectric plate.

[0013] A further technical solution is: the distance between the partially reflective cover plate and the metal floor is 44.6 mm.

[0014] The beneficial technical effect of the present invention is that: a polarization reconfigurable Fabry-Perot resonant cavity antenna of the present invention is provided by a partially reflecting cover plate, a patch antenna, a second dielectric plate, a metal floor and a third dielectric plate which are arranged in parallel from top to bottom. The patch antenna is located in a Fabry-Perot resonant cavity formed by the partially reflecting cover plate and the metal floor as a feed antenna. A polarization reconfigurable feeding network is arranged on the lower surface of the third dielectric plate, so that the antenna can radiate different polarized waves, and polarization reconstruction can be performed to achieve arbitrary switching of different polarization modes, so that polarization mismatch can be avoided without carrying multiple antennas on the wireless communication system platform, the number of antennas carried on the wireless communication system platform is reduced, and the weight and production cost of the wireless communication system platform are reduced. The structure is simple. At the same time, multiple square metal patches and corresponding cross-shaped metal patches are arranged on the upper and lower surfaces of the first dielectric plate respectively, so that the reflection phase of the partially reflecting cover plate can be positively correlated with the change of frequency, so that the antenna can obtain a wider 3-dB gain bandwidth, and the antenna can obtain a larger gain without forming an array. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0016] Figure 1 A schematic diagram of the layered structure of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0017] Figure 2 A schematic structural diagram of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0018] Figure 3 A schematic structural diagram of a single partial reflection unit of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of the back structure of a single partial reflection unit of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0020] Figure 5 A schematic diagram of the installation structure of a patch antenna, a second dielectric plate and a metal floor of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0021] Figure 6 A schematic structural diagram of a polarization reconfigurable feeding network of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0022] Figure 7 A simulation result diagram of the relationship between the reflectivity and frequency of a single partial reflection unit of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0023] Figure 8 A diagram of simulation results of the relationship between the reflection phase and frequency of a single partial reflection unit of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0024] Fig. 9 A diagram showing the simulation results of the relationship between the return loss and frequency of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0025] Fig.10 A simulation result diagram of the relationship between the axial ratio and frequency of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention;

[0026] Fig.11 The far-field radiation pattern of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention when operating in a left-handed circular polarization state at 3.5 GHz when phi=0°;

[0027] Fig.12 The far-field radiation pattern of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention when operating in a left-handed circular polarization state at 3.5 GHz with phi=90°;

[0028] Fig.13 The far-field radiation pattern of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention when operating in a right-hand circular polarization state at 3.5 GHz with phi=0°;

[0029] Fig.14 The far-field radiation pattern of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention when operating in a right-hand circular polarization state at 3.5 GHz with phi=90°;

[0030] Fig.15 The far-field radiation pattern of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention when operating in a linear polarization state at 3.5 GHz with phi=0°;

[0031] Fig.16 The far-field radiation pattern of the polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention when operating in a linear polarization state at 3.5 GHz with phi=90°;

[0032] Fig.17 A diagram of simulation results of the relationship between gain and frequency of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention.

[0033] Explanation of the symbols in the figure: 1. square metal patch; 2. first dielectric plate; 201. square area; 3. cross-shaped metal patch; 301. first strip metal patch; 302. second strip metal patch; 4. patch antenna; 401. first cut corner; 402. second cut corner; 403. first branch; 404. second branch; 5. second dielectric plate; 6. metal floor; 61. H-shaped gap; 611. first gap; 612. second gap; 7. third dielectric plate; 8. polarization reconfigurable feeding network; 81. one-to-two Wilkinson power divider; 82. first 90° phase shifter; 83. second 90° phase shifter; 8 4. First E-type feed line; 841. First microstrip feed line; 842. Second microstrip feed line; 843. Third microstrip feed line; 85. Second U-type feed line; 851. Fourth microstrip feed line; 852. Circular arc feed line; 853. Fifth microstrip feed line; 854. Sixth microstrip feed line; 861. First PIN diode; 862. Second PIN diode; 863. Third PIN diode; 864. Fourth PIN diode; 865. Fifth PIN diode; 866. Sixth PIN diode; 867. Seventh PIN diode; 868. Eighth PIN diode; 87. Isolation resistor; 9. Feeding port; DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0036] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0037] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0038] See also Figures 1 to 6 As shown, Figure 1 A schematic diagram of the layered structure of a polarization reconfigurable Fabry-Perot cavity antenna provided in an embodiment of the present invention, wherein the polarization reconfigurable Fabry-Perot cavity antenna comprises a partially reflective cover plate, a patch antenna 4, a second dielectric plate 5, a metal floor 6 and a third dielectric plate 7 which are arranged in parallel from top to bottom, wherein the partially reflective cover plate comprises a first dielectric plate 2, wherein the upper surface of the first dielectric plate 2 is provided with a plurality of evenly spaced square metal patches 1, and the lower surface of the first dielectric plate 2 is provided with a cross-shaped metal patch 3 corresponding to each of the square metal patches 1, wherein the partially reflective cover plate and the metal floor 6 constitute a Fabry-Perot cavity, and the lower surface of the third dielectric plate 7 is provided with a polarization reconfigurable feeding network 8.

[0039] The square metal patch 1 and the cross-shaped metal patch 3 are arranged relative to each other in the center. The partially reflective cover plate, the patch antenna 4, the second dielectric plate 5, the metal floor 6 and the third dielectric plate 7 are arranged relative to each other in the center in sequence. The first dielectric plate 2 can be made of a plate with a thickness of 2 mm and a dielectric constant of 3.5, and the second dielectric plate 5 and the metal floor 6 can both be made of a plate with a thickness of 1 mm and a dielectric constant of 2.65. The metal floor 6 and the polarization reconfigurable feeding network 8 are respectively arranged on the upper surface and the lower surface of the third dielectric plate 7. The polarization reconfigurable Fabry-Perot resonant cavity antenna is composed of a partially reflecting cover plate, a patch antenna 4, a second dielectric plate 5, a metal floor 6 and a third dielectric plate 7 which are arranged in parallel from top to bottom. The patch antenna 4 is located in the Fabry-Perot resonant cavity formed by the partially reflecting cover plate and the metal floor 6 as a feed antenna. A polarization reconfigurable feeding network 8 is arranged on the lower surface of the third dielectric plate 7 so that the antenna can radiate waves of different polarizations and can perform polarization reconstruction to achieve arbitrary switching of different polarization modes, so that polarization mismatch can be avoided without carrying multiple antennas on the wireless communication system platform, the number of antennas carried on the wireless communication system platform can be reduced, and the weight and production cost of the wireless communication system platform can be reduced. The structure is simple. At the same time, multiple square metal patches 1 and cross-shaped metal patches 3 corresponding to the square metal patches 1 are respectively arranged on the upper and lower surfaces of the first dielectric plate 2, so that the reflection phase of the partially reflecting cover plate can be positively correlated with the change of frequency, so that the antenna can obtain a wider 3-dB gain bandwidth, and the antenna can obtain a larger gain without forming an array.

[0040] Specifically, in this embodiment, the distance between the partially reflective cover plate and the metal floor 6 is 44.6 mm. The partially reflective cover plate is located above the metal floor 6 at about half the antenna working wavelength. Preferably, the patch antenna 4 is provided on the upper surface of the second dielectric plate 5, and the second dielectric plate 5 is fixed at 1.4 mm above the metal floor 6, then the patch antenna 4 is located 1.4 mm above the metal floor 6 as a feed antenna.

[0041] Specifically, in this embodiment, the plurality of square metal patches 1 are distributed in a 7×7 matrix on the upper surface of the first dielectric plate 2 , and the cross-shaped metal patches 3 correspond one to one to the square metal patches 1 .

[0042] Specifically, in this embodiment, the cross-shaped metal patch 3 includes a first strip metal patch 301 and a second strip metal patch 302. The first strip metal patch 301 and the second strip metal patch 302 have the same size and are stacked vertically with each other. The first strip metal patch 301 and the second strip metal patch 302 are stacked vertically with their centers relatively close to each other.

[0043] Specifically, the partially reflective cover plate is divided into a plurality of partially reflective units by the square metal patch 1, each of the partially reflective units includes a cross-shaped metal patch 3, a square area 201 of the first dielectric plate 2 corresponding to the top of the cross-shaped metal patch 3, and the square metal patch 1 corresponding to the cross-shaped metal patch 3, the width of the first strip metal patch 301 and the second strip metal patch 302 are both 6 mm, the side length of the square metal patch 1 is 17.5 mm, the side length of the partially reflective unit is 20 mm, and accordingly, the length of the first strip metal patch 301 and the second strip metal patch 302 are both 20 mm.

[0044] Specifically, in this embodiment, one set of diagonal edges of the patch antenna 4 are respectively formed with cut corners, and the two cut corners can be the first cut corner 401 and the second cut corner 402, respectively. One set of edges of the opposite sides of the patch antenna 4 are extended outwards at the midpoints to form branches, and the two branches are respectively the first branch 403 and the second branch 404. By forming cut corners on one set of diagonal edges of the patch antenna 4, better circular polarization characteristics can be obtained; by extending outwards at the midpoints of the edges of one set of opposite sides of the patch antenna 4, branches are respectively formed to improve the impedance matching characteristics of the antenna. Among them, the cut corners can be formed by cutting a set of diagonal isosceles right triangles with a side length of 3mm of the patch antenna 4, and the branches can be rectangular structures, and the length of the branches is 5mm and the width is 1.4mm.

[0045] Specifically, in this embodiment, the metal floor 6 is provided with four H-shaped slots 61 around the center, and the H-shaped slots 61 include a first slot 611 and a second slot 612 respectively provided at both ends of the first slot 611, and the second slot 612 is vertically connected to the first slot 611. The first slot 611 and the second slot 612 are both in the shape of long strips, and the four H-shaped slots 61 have the same size. The patch antenna 4 corresponds to one of the second slots 612 and part of the first slot 611 of all the H-shaped slots 61, so that the H-shaped slot 61 couples and excites the patch antenna 4 above, which can expand the working bandwidth of the antenna. The four H-shaped slots 61 can be obtained by rotating 90° around the Z axis in sequence, and the interval between two opposite H-shaped slots 61 can be 8 mm.

[0046] Specifically, in this embodiment, the polarization reconfigurable feeding network includes a feeding port 9, a one-to-two Wilkinson power divider 81, a first 90° phase shifter 82, a second 90° phase shifter 83, a first E-type feeder 84, a second U-type feeder 85, a first PIN diode 861, a second PIN diode 862, a third PIN diode 863, a fourth PIN diode 864, a fifth PIN diode 865, a sixth PIN diode 866, a seventh PIN diode 867 and an eighth PIN diode 868, the input branch of the one-to-two Wilkinson power divider 81 is connected to the feeding port 9, an isolation resistor 87 is connected between the two output branches of the one-to-two Wilkinson power divider 81, and one of the output branches of the one-to-two Wilkinson power divider 81 is respectively connected to the first PIN diode 861 The first PIN diode 861 is connected to one end of the first 90° phase shifter 82 and the second PIN diode 862 in sequence, and then connected to the second U-shaped feeder 85. The other end of the third PIN diode 863 is connected to the second U-shaped feeder 85 via the fourth PIN diode 864. The other output branch is connected to one end of the fifth PIN diode 865 and one end of the seventh PIN diode 867 respectively. The other end of the fifth PIN diode 865 is connected to the first E-shaped feeder 84 via the sixth PIN diode 866. The other end of the seventh PIN diode 867 is connected to the second 90° phase shifter 83 and the eighth PIN diode 868 in sequence, and then connected to the first E-shaped feeder 84. By setting eight PIN diodes to control the transmission path of the microwave signal, the reconfiguration of left-hand circular polarization, right-hand circular polarization and linear polarization is realized. The first E-type feed line 84 and the second U-type feed line 85 excite the patch antenna 4 through the H-type slot 61 on the metal floor 6, so as to perform slot coupling feeding on the patch antenna 4, which is beneficial to expand the working bandwidth of the antenna. The resistance value of the isolation resistor 87 is 100Ω.

[0047] Among them, the first PIN diode 861 and the second PIN diode 862 are the first group of PIN tubes, the third PIN diode 863 and the fourth PIN diode 864 are the second group of PIN tubes, the fifth PIN diode 865 and the sixth PIN diode 866 are the third group of PIN tubes, and the seventh PIN diode 867 and the eighth PIN diode 868 are the fourth group of PIN tubes. When the first group of PIN tubes and the third group of PIN tubes are in the on state and the second group of PIN tubes and the fourth group of PIN tubes are in the off state, the antenna radiates left-handed circularly polarized electromagnetic waves; when the first group of PIN tubes and the third group of PIN tubes are in the off state and the second group of PIN tubes and the fourth group of PIN tubes are in the on state, the antenna radiates right-handed circularly polarized electromagnetic waves; when the first group of PIN tubes and the fourth group of PIN tubes are in the on state and the second group of PIN tubes and the third group of PIN tubes are in the off state, the antenna radiates linearly polarized electromagnetic waves.

[0048] Specifically, the first E-type feed line 84 includes a first microstrip feed line 841, two second microstrip feed lines 842 disposed at both ends of the first microstrip feed line 841 and connected to the first microstrip feed line 841, and two third microstrip feed lines 843 respectively connected to the second microstrip feed lines 842, the first microstrip feed line 841 is an input feed line of the first E-type feed line 84, the sixth PIN diode 866 and the eighth PIN diode 868 are both connected to the first microstrip feed line 841. The second microstrip feed line 842 is respectively vertically connected to the first microstrip feed line 841 and the corresponding third microstrip feed line 843.

[0049] Specifically, the second U-shaped feed line 85 includes a fourth microstrip feed line 851, a circular arc feed line 852, two fifth microstrip feed lines 853 and two sixth microstrip feed lines 854, the fourth microstrip feed line 851 is connected to the middle part of the circular arc feed line 852, the two ends of the circular arc feed line 852 are respectively connected to one of the fifth microstrip feed lines 853, the sixth microstrip feed line 854 is connected to the fifth microstrip feed line 853, the fourth microstrip feed line 851 is the input feed line of the second U-shaped feed line 85, and the second PIN diode 862 and the fourth PIN diode 864 are both connected to the fourth microstrip feed line 851.

[0050] See also Figure 7 and Figure 8 As shown, Figure 7 and Figure 8The simulation result diagrams of the relationship between the reflectivity and frequency of a single partial reflection unit of the polarization reconfigurable Fabry-Perot cavity antenna provided by the embodiment of the present invention and the simulation result diagrams of the relationship between the reflection phase and frequency are respectively shown. The simulation results are obtained by simulating and calculating the reflectivity and reflection phase of the partial reflection cover plate using the commercial simulation software ANSYS HFSS_18.0, as shown in FIG. Figure 7 and Figure 8 As shown, the reflectivity of the partially reflective cover plate is greater than 0.6 in the working frequency band of 3.3 GHz to 3.9 GHz, and the reflection phase gradually increases with the increase of frequency, showing a positive correlation trend.

[0051] See also Fig. 9 and Fig.10 As shown, Fig. 9 and Fig.10 The simulation result diagrams of the relationship between the return loss and the frequency of the polarization reconfigurable Fabry-Perot cavity antenna provided in the embodiment of the present invention and the simulation result diagrams of the relationship between the axial ratio and the frequency are respectively shown. The simulation result diagrams are obtained by simulating and calculating the S11 parameter (i.e., the self-reflection coefficient of the feeding port) and the Axial Ratio parameter (i.e., the axial ratio) of the antenna using the commercial simulation software ANSYS HFSS_18.0. Fig. 9 and Fig.10 As shown, when the return loss is greater than 10dB and the axial ratio is less than 3dB, the operating frequency band covered by left-hand circular polarization is 3.44GHz~4.11GHz, the operating frequency band covered by right-hand circular polarization is 3.15GHz~4.09GHz, and the operating frequency band covered by linear polarization is 3.28GHz~3.62GHz.

[0052] like Figures 11 to 16 As shown, no matter it is left-hand circular polarization, right-hand circular polarization or linear polarization, the maximum radiation direction of the antenna is +z axis, without deviation and lobe phenomenon, and within the 3-dB lobe width, the cross-polarization level is basically 20dB lower than the main polarization.

[0053] Fig.17 The simulation results show the relationship between the gain and frequency of the polarization reconfigurable Fabry-Perot cavity antenna, as shown in Fig.17 As shown, the maximum gain obtained by left-hand circular polarization is 12.78dB, the maximum gain obtained by right-hand circular polarization is 12.13dB, and the maximum gain obtained by linear polarization is 12.65dB, and all of them maintain relatively stable gains within a wider operating frequency band.

[0054] In summary, a polarization reconfigurable Fabry-Perot resonant cavity antenna of the present invention is provided with a partially reflecting cover plate, a patch antenna, a second dielectric plate, a metal floor and a third dielectric plate arranged in parallel from top to bottom. The patch antenna is located in a Fabry-Perot resonant cavity formed by the partially reflecting cover plate and the metal floor as a feed antenna. A polarization reconfigurable feeding network is provided on the lower surface of the third dielectric plate, so that the antenna can radiate different polarized waves, and polarization reconstruction can be performed to achieve arbitrary switching of different polarization modes, so that polarization mismatch can be avoided without carrying multiple antennas on the wireless communication system platform, the number of antennas carried on the wireless communication system platform is reduced, and the weight and production cost of the wireless communication system platform are reduced. The structure is simple. At the same time, multiple square metal patches and corresponding cross-shaped metal patches are respectively provided on the upper and lower surfaces of the first dielectric plate, so that the reflection phase of the partially reflecting cover plate can be positively correlated with the change of frequency, so that the antenna can obtain a wider 3-dB gain bandwidth, and the antenna can obtain a larger gain without forming an array.

[0055] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A polarization reconfigurable Fabry-Perot cavity antenna, characterized in that: The invention comprises a partially reflective cover plate, a patch antenna, a second dielectric plate, a metal floor and a third dielectric plate which are arranged in parallel from top to bottom. The partially reflective cover plate comprises a first dielectric plate. The upper surface of the first dielectric plate is provided with a plurality of evenly spaced square metal patches. The lower surface of the first dielectric plate is provided with a cross-shaped metal patch corresponding to each of the square metal patches. The partially reflective cover plate and the metal floor constitute a Fabry-Perot resonant cavity. The lower surface of the third dielectric plate is provided with a polarization reconfigurable feeding network. The polarization reconfigurable feeding network comprises a feeding port, a one-to-two Wilkinson power divider, a first 90° phase shifter, a second 90° phase shifter, a first E-type feeder, a second U-type feeder, a first PIN diode, a second PIN diode, a third PIN diode, a fourth PIN diode, a fifth PIN diode, a sixth PIN diode, a seventh PIN diode and an eighth PIN diode. The input branch of the one-to-two Wilkinson power divider is connected to the feeding port, and an isolation resistor is connected between the two output branches of the one-to-two Wilkinson power divider, wherein one of the output branches is respectively connected to one end of the first PIN diode and one end of the third PIN diode, the other end of the first PIN diode is sequentially connected to the first 90° phase shifter and the second PIN diode, and then connected to the second U-shaped feeder, and the other end of the third PIN diode is connected to the second U-shaped feeder via the fourth PIN diode; the other output branch is respectively connected to one end of the fifth PIN diode and one end of the seventh PIN diode, the other end of the fifth PIN diode is connected to the first E-type feeder via the sixth PIN diode, and the other end of the seventh PIN diode is sequentially connected to the second 90° phase shifter and the eighth PIN diode, and then connected to the first E-type feeder.

2. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: The cross-shaped metal patch includes a first strip-shaped metal patch and a second strip-shaped metal patch. The first strip-shaped metal patch and the second strip-shaped metal patch have the same size and are vertically stacked with each other.

3. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 2, characterized in that: The partially reflective cover plate is divided into a plurality of partially reflective units by the square metal patch, each of the partially reflective units includes a cross-shaped metal patch, a square area of ​​the first dielectric plate corresponding to the cross-shaped metal patch, and the square metal patch corresponding to the cross-shaped metal patch, the width of the first strip metal patch and the second strip metal patch are both 6 mm, the side length of the square metal patch is 17.5 mm, and the side length of the partially reflective unit is 20 mm.

4. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: A group of diagonal edges of the patch antenna are respectively formed with cut corners, and a group of opposite side edges of the patch antenna are respectively extended outwards to form branches at midpoints.

5. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: The metal floor is provided with four H-shaped gaps around the center, and the H-shaped gaps include a first gap and second gaps respectively provided at two ends of the first gap, and the second gaps are vertically connected to the first gaps.

6. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: The first E-type feed line includes a first microstrip feed line, two second microstrip feed lines that are arranged at both sides of the end of the first microstrip feed line and connected to the first microstrip feed line, and two third microstrip feed lines that are respectively connected to the second microstrip feed lines. The first microstrip feed line is an input feed line of the first E-type feed line, and the sixth PIN diode and the eighth PIN diode are both connected to the first microstrip feed line.

7. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: The second U-shaped feed line includes a fourth microstrip feed line, a circular arc feed line, two fifth microstrip feed lines and two sixth microstrip feed lines, the fourth microstrip feed line is connected to the middle part of the circular arc feed line, the two ends of the circular arc feed line are respectively connected to one of the fifth microstrip feed lines, the sixth microstrip feed line is connected to the fifth microstrip feed line, the fourth microstrip feed line is the input feed line of the second U-shaped feed line, and the second PIN diode and the fourth PIN diode are both connected to the fourth microstrip feed line.

8. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: The square metal patches are distributed in a 7×7 matrix on the upper surface of the first dielectric plate.

9. The polarization reconfigurable Fabry-Perot cavity antenna according to claim 1, characterized in that: The distance between the partially reflective cover plate and the metal floor is 44.6 mm.

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