A triple-frequency polarization reconfigurable single-feed patch antenna

Abstract

The invention discloses a three-frequency polarization reconfigurable single-feed patch antenna, comprising a first and a second dielectric substrate, an input port, a PIN diode, an inductor, a capacitor and a voltage module; the first dielectric substrate is located above the second dielectric substrate, and an air layer exists between the two dielectric substrates; a rectangular radiation patch is provided on the top surface of the first dielectric substrate, three sides of the rectangular radiation patch are loaded with open-circuit stubs, the open-circuit stubs are connected to the rectangular radiation patch through PIN diodes, three slits parallel to the adjacent sides are opened inside the rectangular radiation patch, and a PIN diode is bridged at the center of each slit; a floor with slits is provided on the top surface of the second dielectric substrate, and a microstrip feeder of the input port is provided on the bottom surface, and the microstrip feeder of the input port excites the rectangular radiation patch through the slits on the floor. The invention can realize the switching of polarization characteristics in three frequency bands, and has the advantages of diversified functions, flexible design, low profile, low cost, etc.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to a triple-frequency polarization reconfigurable single-feed patch antenna. Background Art

[0002] Reconfigurable antennas have attracted people's attention because of their multifunctional characteristics. Among them, polarization reconfigurable antennas have attracted much attention because of their advantages such as reducing fading losses, increasing system capacity, and suppressing channel interference. In places with dense buildings, a large number of multipath reflections will appear. Circularly polarized antennas can effectively combat the Faraday rotation effect and multipath fading and improve signal quality. In rural areas or open areas on roads where multipath reflections are not significant, polarization is mainly concentrated in the vertical direction. In order to enable the same system to meet multiple communication standards at the same time and be able to switch polarization states according to application needs, the role of multi-frequency polarization reconfigurable antennas is particularly important. Microstrip planar antennas play an important role in modern communication terminals because of their advantages such as light weight, easy processing, low profile and low cost. So far, international scholars have proposed a variety of multi-frequency and polarization reconfigurable technical implementations of patch antennas.

[0003] In 2013, Ahmed Khidre and other scholars published an article titled "Circular Polarization Reconfigurable Wideband E-Shaped Patch Antenna for Wireless Applications" in "IEEE TREANSACTIONS ON ANTENNAS AND PROPAGATION". They loaded a microwave switch on each of the two gaps of the E-shaped radiation patch, and used the opening and closing states of the microwave switch to achieve switching between two working states: left-hand circular polarization at 2.3-2.5GHz, or right-hand circular polarization at 2.3-2.5GHz.

[0004] In 2015, Mohammad M. Fakharian and other scholars published an article titled "Reconfigurable Multiband Extended U-Slot Antenna With Switchable Polarization for Wireless Applications" in the "IEEE ANTENNAS AND PROPAGATION MAGAZINE". They opened a U-shaped slot line on the radiating patch and a slot line on the ground plate, and used a bias circuit to control the PIN diode across the U-shaped slot line to achieve switching between four working states: right-hand circular polarization at 2.4GHz and 5.8GHz, left-hand circular polarization at 2.4GHz and 5.8GHz, linear polarization at 2.4GHz, 3.5GHz and 5.8GHz, or linear polarization at 5.8GHz.

[0005] The existing technologies are investigated and understood as follows:

[0006] In general, in the existing work, the research on polarization reconfigurable and multi-frequency antennas accounts for a considerable proportion, but most of the reconfigurable multi-frequency antennas are concentrated on single-frequency or dual-frequency, and the research on triple-frequency is relatively small. In addition, there are fewer antennas that can switch polarization states in three frequency bands at the same time. Therefore, it is of great significance to design a patch antenna with three-frequency polarization reconfigurable characteristics, single-slot coupled feeding, and simple structure. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and propose a simple and reliable three-frequency polarization reconfigurable single-fed patch antenna that can switch polarization characteristics in three frequency bands and has the advantages of diversified functions, flexible design, low profile and low cost.

[0008] To achieve the above-mentioned purpose, the technical solution provided by the present invention is: a triple-frequency polarization reconfigurable single-feed patch antenna, comprising a first dielectric substrate, a second dielectric substrate, an input port, a first PIN diode, a second PIN diode, a third PIN diode, a fourth PIN diode, a fifth PIN diode, a first inductor, a second inductor, a third inductor, a fourth inductor, a fifth inductor, a sixth inductor, a seventh inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first voltage module, a second voltage module, a third voltage module, a fourth voltage module, a fifth voltage module, a sixth voltage module, and a seventh voltage module;

[0009] The first dielectric substrate is located above the second dielectric substrate, and an air layer exists between the two dielectric substrates;

[0010] A rectangular radiation patch is placed on the top surface of the first dielectric substrate; open short stubs are loaded on three sides of the rectangular radiation patch, namely, a first open short stub, a second open short stub, and a third open short stub, the second open short stub and the third open short stub are located at two non-adjacent sides of the rectangular radiation patch, the second open short stub is connected to the rectangular radiation patch through a second PIN diode, and the third open short stub is connected to the rectangular radiation patch through a third PIN diode; three slits are opened inside the rectangular radiation patch, namely, a first slit, a second slit, a third slit, and a fourth slit. , a second slit, and a third slit, the three slits are parallel to and close to three sides of the rectangular radiation patch, that is, one slit corresponds to one side, the first slit corresponds to the side of the second open short stub, the third slit corresponds to the side of the third open short stub, and the second slit corresponds to the side without the open short stub loaded, a fourth PIN diode is bridged at the center of the first slit, and a second capacitor and a third capacitor are bridged at both ends thereof, a fifth PIN diode is bridged at the center of the third slit, and a fourth capacitor and a fifth capacitor are bridged at both ends thereof;

[0011] The top surface of the first dielectric substrate is provided with a first pad, a second pad, a third pad, a fourth pad, and a fifth pad; the second open-circuit stub is connected to the second pad through a third inductor and then connected to a fourth voltage module; the third open-circuit stub is connected to the fifth pad through a sixth inductor and then connected to a seventh voltage module; the fourth inductor and the fifth inductor are respectively loaded at both ends of the side of the rectangular radiation patch that is not loaded with the open-circuit stub; the fourth inductor is connected to the third pad and then connected to the fifth voltage module, and the fifth inductor is connected to the fourth pad and then connected to the sixth voltage module; the side of the rectangular radiation patch that is loaded with the first open-circuit stub is loaded with a seventh inductor, and the seventh inductor is connected to the first pad and then connected to the third voltage module;

[0012] A floor with a gap is arranged on the top surface of the second dielectric substrate, and a sixth pad, a seventh pad and the first, second and third microstrip feeders of the input port are arranged on the bottom surface thereof. The first, second and third microstrip feeders form an L-shaped structure, and the first microstrip feeder and the second microstrip feeder are on the same straight line. One end of the second microstrip feeder is connected to the first microstrip feeder through a first capacitor, and the other end thereof is connected to the sixth pad through a first inductor and then to a first voltage module. A first PIN diode is bridged between the second microstrip feeder and the third microstrip feeder, and the third microstrip feeder is connected to the seventh pad through a second inductor and then to a second voltage module. The first, second and third microstrip feeders of the input port excite the rectangular radiation patch through the gap on the floor.

[0013] Furthermore, the opening and closing state of the PIN diode is controlled by controlling the voltage of the voltage module, thereby realizing polarization reconfiguration, as follows:

[0014] When the second and fourth PIN diodes are in the closed state and the third and fifth PIN diodes are in the open state, the three frequency bands of the antenna are in left-hand circular polarization, left-hand circular polarization and right-hand circular polarization from low frequency to high frequency;

[0015] When the third and fifth PIN diodes are in the closed state and the second and fourth PIN diodes are in the open state, the three frequency bands of the antenna are in right-hand circular polarization, right-hand circular polarization and left-hand circular polarization from low frequency to high frequency;

[0016] When the fourth and fifth PIN diodes are in a closed state and the second and third PIN diodes are in an open state, the three frequency bands of the antenna are all in linear polarization.

[0017] Furthermore, the microstrip feed line of the input port can change the feed line structure by controlling the state of the first PIN diode to achieve good impedance matching in each polarization state; when the three frequency bands of the antenna are in left-hand circular polarization, left-hand circular polarization and right-hand circular polarization from low frequency to high frequency, the first PIN diode is in an open state; when the three frequency bands of the antenna are in right-hand circular polarization, right-hand circular polarization and left-hand circular polarization from low frequency to high frequency, the first PIN diode is in an open state; when the three frequency bands of the antenna are all in linear polarization, the first PIN diode is in a closed state.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] 1. By loading open-circuit stubs and trenching lines to disturb the field distribution of high-order modes, and utilizing the opening and closing states of PIN diodes to change the structure of the radiation unit, multi-frequency polarization reconfiguration can be achieved without adding additional radiators, reducing processing complexity and antenna volume.

[0020] 2. When a single slot is used for feeding, polarization reconfiguration is achieved by changing the structure of the radiating unit, avoiding the complex circuit during dual feeding and effectively simplifying the feeding structure of the antenna; and a PIN diode is loaded on the feed line, and the length of the feed line and the loading of the branch are changed by controlling the opening and closing state of the PIN diode, so that the antenna can easily achieve good impedance matching under various working conditions.

[0021] 3. The microstrip feed line at the input port excites the rectangular radiating patch through the gap in the floor, and the feeding structure has low interference to the radiating patch. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a top view of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention.

[0023] Figure 2It is a top view of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention.

[0024] Figure 3 It is a side view of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention.

[0025] Figure 4 is the reflection coefficient (S) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention in state 1 11 Parameters) simulation results.

[0026] Figure 5 This is a simulation result diagram of the gain and axial ratio of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention in state 1.

[0027] Figure 6a It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 2.45 GHz in state 1.

[0028] Figure 6b It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 3.44 GHz in state 1.

[0029] Figure 6c It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 4.29 GHz in state 1.

[0030] Figure 7 The reflection coefficient (S) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention in state 2 11 Parameters) simulation results.

[0031] Figure 8 A diagram of simulation results of the gain and axial ratio of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention in state 2.

[0032] Figure 9a It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 2.46 GHz in state 2.

[0033] Figure 9b It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 3.44 GHz in state 2.

[0034] Fig.9c It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 4.29 GHz in state 2.

[0035] Fig.10 The reflection coefficient (S) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention in state 3 11 Parameters) simulation results.

[0036] Fig.11 A diagram of simulation results of the gain and axial ratio of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention in state 3.

[0037] Fig.12a It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 2.74 GHz in state 3.

[0038] Figure 12b It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 3.56 GHz in state 3.

[0039] Fig.12c It is the simulation result of the radiation pattern (xoz plane and yoz plane) of the triple-frequency polarization reconfigurable single-feed patch antenna of the present invention at a frequency of 4.35 GHz in state 3. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with specific embodiments.

[0041] See also Figures 1 to 3 As shown, the triple-frequency polarization reconfigurable single-feed patch antenna provided in this embodiment includes a first dielectric substrate 1, a second dielectric substrate 2, an input port, a first PIN diode D1, a second PIN diode D2, a third PIN diode D3, a fourth PIN diode D4, a fifth PIN diode D5, a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a first voltage module V1, a second voltage module V2, a third voltage module V3, a fourth voltage module V4, a fifth voltage module V5, a sixth voltage module V6, and a seventh voltage module V7.

[0042] The first dielectric substrate 1 is located above the second dielectric substrate 2, and an air layer 3 exists between the two dielectric substrates.

[0043] A rectangular radiation patch 11 is placed on the top surface of the first dielectric substrate 1; three sides of the rectangular radiation patch 11 are loaded with open short stubs, which are respectively a first open short stub 12, a second open short stub 13, and a third open short stub 14. The second open short stub 13 and the third open short stub 14 are located at two non-adjacent sides of the rectangular radiation patch 11. The second open short stub 13 is connected to the rectangular radiation patch 11 through a second PIN diode D2, and the third open short stub 14 is connected to the rectangular radiation patch 11 through a third PIN diode D3; three gaps are opened inside the rectangular radiation patch 11, which are respectively a first gap 15, a second gap 16, a second gap 17, a third gap 18, a third gap 19, a third gap 20, a third gap 21, a third gap 22, a third gap 23, a third gap 24, a third gap 25, a third gap 26, a third gap 27, a third gap 28, a third gap 29, a third gap 30, a third gap 31, a third gap 32, a third gap 33, a third gap 34, a third gap 35, a third gap 36, a third gap 37, a third gap 38, a third gap 3 ... , a second slot 16, and a third slot 17, the three slots are parallel to and close to three sides of the rectangular radiation patch 11, that is, one slot corresponds to one side, the first slot 15 corresponds to the side of the second open short-circuit stub 13, the third slot 17 corresponds to the side of the third open short-circuit stub 14, and the second slot 16 corresponds to the side without the open short-circuit stub loaded, a fourth PIN diode D4 is bridged at the center of the first slot 15, and a second capacitor C2 and a third capacitor C3 are bridged at both ends thereof, a fifth PIN diode D5 is bridged at the center of the third slot 17, and a fourth capacitor C4 and a fifth capacitor C5 are bridged at both ends thereof.

[0044] The top surface of the first dielectric substrate 1 is provided with a first pad 18, a second pad 19, a third pad 20, a fourth pad 21, and a fifth pad 22; the second open-circuit stub 13 is connected to the second pad 19 through a third inductor L3 and then connected to a fourth voltage module V4; the third open-circuit stub 14 is connected to the fifth pad 22 through a sixth inductor L6 and then connected to a seventh voltage module V7; the fourth inductor L4 and the fifth inductor L5 are respectively loaded at both ends of the side of the rectangular radiation patch 11 that is not loaded with the open-circuit stub; the fourth inductor L4 is connected to the third pad 20 and then connected to the fifth voltage module V5, and the fifth inductor L5 is connected to the fourth pad 21 and then connected to the sixth voltage module V6; the side of the rectangular radiation patch 11 that is loaded with the first open-circuit stub 12 is loaded with a seventh inductor L7, and the seventh inductor L7 is connected to the first pad 18 and then connected to the third voltage module V3.

[0045] A floor 4 with a gap 5 is provided on the top surface of the second dielectric substrate 2, and a sixth pad 8, a seventh pad 10 and the first, second and third microstrip feed lines 6, 7 and 9 of the input port are provided on the bottom surface thereof. The first, second and third microstrip feed lines 6, 7 and 9 form an L-shaped structure, and the first microstrip feed line 6 and the second microstrip feed line 7 are on the same straight line. One end of the second microstrip feed line 7 is connected to the first microstrip feed line 6 through a first capacitor C1, and the other end thereof is connected to the sixth pad 8 through a first inductor L1 and then connected to a first voltage module V1. A first PIN diode D1 is bridged between the second microstrip feed line 7 and the third microstrip feed line 9, and the third microstrip feed line 9 is connected to the seventh pad 10 through a second inductor L2 and then connected to a second voltage module V2; the first, second and third microstrip feed lines 6, 7 and 9 of the input port excite the rectangular radiation patch 11 through the gap 5 on the floor 4.

[0046] The opening and closing state of the PIN diode is controlled by controlling the voltage of the voltage module, thereby realizing polarization reconfiguration, as follows:

[0047] When the second and fourth PIN diodes D2 and D4 are in the closed state and the third and fifth PIN diodes D3 and D5 are in the open state, the three frequency bands of the antenna are in left circular polarization, left circular polarization and right circular polarization from low frequency to high frequency (state 1).

[0048] When the third and fifth PIN diodes D3 and D5 are in the closed state and the second and fourth PIN diodes D2 and D4 are in the open state, the three frequency bands of the antenna are in right circular polarization, right circular polarization and left circular polarization from low frequency to high frequency (state 2).

[0049] When the fourth and fifth PIN diodes D4 and D5 are in a closed state and the second and third PIN diodes D2 and D3 are in an open state, the three frequency bands of the antenna are all in linear polarization (state 3).

[0050] The microstrip feed line of the input port can change the feed line structure by controlling the state of the first PIN diode D1 to achieve good impedance matching in each polarization state; when the three frequency bands of the antenna are in left-hand circular polarization, left-hand circular polarization and right-hand circular polarization from low frequency to high frequency, the first PIN diode D1 is in an open state; when the three frequency bands of the antenna are in right-hand circular polarization, right-hand circular polarization and left-hand circular polarization from low frequency to high frequency, the first PIN diode D1 is in an open state; when the three frequency bands of the antenna are all in linear polarization, the first PIN diode D1 is in a closed state.

[0051] See also Figure 4As shown in FIG. 1 , the simulation result of the reflection coefficient of the triple-frequency polarization reconfigurable single-feed patch antenna in state 1 is shown. As can be seen from the figure, the impedance bandwidth of the antenna is 2.43-2.56 GHz, 3.32-3.42 GHz and 4.17-4.55 GHz. The antenna achieves good impedance matching in the passband.

[0052] See also Figure 5 As shown, the simulation results of the gain and axial ratio in the normal direction of the three frequency bands of the above-mentioned three-frequency polarization reconfigurable single-fed patch antenna in this embodiment in state 1 are shown. It can be seen from the figure that the 3-dB axial ratio bandwidth of the three frequency bands of the antenna in the normal direction is 2.44-2.47GHz, 3.43-3.45GHz and 4.28-4.31GHz, respectively, and the circular polarization characteristics are left-hand circular polarization, left-hand circular polarization and right-hand circular polarization, respectively, and the gain in the normal direction is 7.27dBi, 7.32dBi, and 7.56dBi, respectively. The antenna can achieve a low axial ratio in the passband and has good circular polarization characteristics.

[0053] See also Figure 6a , 6b 6c, which shows the radiation pattern simulation results of the triple-frequency polarization reconfigurable single-feed patch antenna in this embodiment at three passband center frequencies in state 1. It can be seen from the figure that the antenna achieves good directional radiation characteristics in both the xoz plane and the yoz plane.

[0054] See also Figure 7 As shown in FIG. 1 , the simulation result of the reflection coefficient of the triple-frequency polarization reconfigurable single-feed patch antenna in state 2 is shown. As can be seen from the figure, the impedance bandwidth of the antenna is 2.44-2.56 GHz, 3.33-3.44 GHz and 4.18-4.55 GHz. The antenna achieves good impedance matching in the passband.

[0055] See also Figure 8 As shown, the simulation results of the gain and axial ratio in the normal direction of the three frequency bands of the above-mentioned three-frequency polarization reconfigurable single-fed patch antenna in this embodiment in state 2 are shown. It can be seen from the figure that the 3-dB axial ratio bandwidth of the three frequency bands of the antenna in the normal direction is 2.44-2.46GHz, 3.43-3.46GHz and 4.28-4.30GHz, respectively, and the circular polarization characteristics are left-hand circular polarization, left-hand circular polarization and right-hand circular polarization, respectively, and the gain in the normal direction is 7.07dBi, 7.67dBi, and 7.66dBi, respectively. The antenna can achieve a low axial ratio in the passband and has good circular polarization characteristics.

[0056] See also Figure 9a , 9b9c shows the radiation pattern simulation results of the triple-frequency polarization reconfigurable single-feed patch antenna in state 2 at three passband center frequencies. It can be seen from the figure that the antenna achieves good directional radiation characteristics in both the xoz plane and the yoz plane.

[0057] See also Fig.10 As shown in FIG. 1 , the simulation result of the reflection coefficient of the triple-frequency polarization reconfigurable single-feed patch antenna in state 3 is shown. As can be seen from the figure, the impedance bandwidth of the antenna is 2.71-2.77 GHz, 3.54-3.58 GHz and 4.30-4.40 GHz. The antenna achieves good impedance matching in the passband.

[0058] See also Fig.11 As shown, it shows the gain in the normal direction in the three frequency bands of 2.71-2.77 GHz, 3.54-3.58 GHz and 4.30-4.40 GHz of the above-mentioned three-frequency polarization reconfigurable single-fed patch antenna of this embodiment when in state 3, and the gain peaks of the three frequency bands are 8.16 dBi, 9.21 dBi and 9.81 dBi respectively.

[0059] See also Fig.12a , 12b 12c, which respectively show the radiation pattern simulation results of the triple-frequency polarization reconfigurable single-feed patch antenna in this embodiment at 2.74 GHz, 3.56 GHz and 4.35 GHz in state 3. It can be seen from the figure that the antenna achieves good directional radiation characteristics in both the xoz plane and the yoz plane.

[0060] The above-described embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A triple-frequency polarization reconfigurable single-feed patch antenna, characterized in that: It includes a first dielectric substrate, a second dielectric substrate, an input port, a first PIN diode, a second PIN diode, a third PIN diode, a fourth PIN diode, a fifth PIN diode, a first inductor, a second inductor, a third inductor, a fourth inductor, a fifth inductor, a sixth inductor, a seventh inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first voltage module, a second voltage module, a third voltage module, a fourth voltage module, a fifth voltage module, a sixth voltage module, and a seventh voltage module; The first dielectric substrate is located above the second dielectric substrate, and an air layer exists between the two dielectric substrates; A rectangular radiation patch is placed on the top surface of the first dielectric substrate; open short stubs are loaded on three sides of the rectangular radiation patch, namely, a first open short stub, a second open short stub, and a third open short stub, the second open short stub and the third open short stub are located at two non-adjacent sides of the rectangular radiation patch, the second open short stub is connected to the rectangular radiation patch through a second PIN diode, and the third open short stub is connected to the rectangular radiation patch through a third PIN diode; three slits are opened inside the rectangular radiation patch, namely, a first slit, a second slit, a third slit, and a fourth slit. , a second slit, and a third slit, the three slits are parallel to and close to three sides of the rectangular radiation patch, that is, one slit corresponds to one side, the first slit corresponds to the side of the second open short stub, the third slit corresponds to the side of the third open short stub, and the second slit corresponds to the side without the open short stub loaded, a fourth PIN diode is bridged at the center of the first slit, and a second capacitor and a third capacitor are bridged at both ends thereof, a fifth PIN diode is bridged at the center of the third slit, and a fourth capacitor and a fifth capacitor are bridged at both ends thereof; The top surface of the first dielectric substrate is provided with a first pad, a second pad, a third pad, a fourth pad, and a fifth pad; the second open-circuit stub is connected to the second pad through a third inductor and then connected to a fourth voltage module; the third open-circuit stub is connected to the fifth pad through a sixth inductor and then connected to a seventh voltage module; the fourth inductor and the fifth inductor are respectively loaded at both ends of the side of the rectangular radiation patch that is not loaded with the open-circuit stub; the fourth inductor is connected to the third pad and then connected to the fifth voltage module, and the fifth inductor is connected to the fourth pad and then connected to the sixth voltage module; the side of the rectangular radiation patch that is loaded with the first open-circuit stub is loaded with a seventh inductor, and the seventh inductor is connected to the first pad and then connected to the third voltage module; The top surface of the second dielectric substrate is provided with a floor with a gap, and the bottom surface thereof is provided with a sixth pad, a seventh pad, and the first, second, and third microstrip feeders of the input port, the first, second, and third microstrip feeders form an L-shaped structure, and the first microstrip feeder and the second microstrip feeder are on the same straight line, one end of the second microstrip feeder is connected to the first microstrip feeder through a first capacitor, and the other end thereof is connected to the sixth pad through a first inductor and then connected to a first voltage module, a first PIN diode is bridged between the second microstrip feeder and the third microstrip feeder, and the third microstrip feeder is connected to the seventh pad through a second inductor and then connected to a second voltage module; the first, second, and third microstrip feeders of the input port excite the rectangular radiation patch through the gap on the floor; The opening and closing state of the PIN diode is controlled by controlling the voltage of the voltage module, thereby realizing polarization reconfiguration, as follows: When the second and fourth PIN diodes are in the closed state and the third and fifth PIN diodes are in the open state, the three frequency bands of the antenna are in left-hand circular polarization, left-hand circular polarization and right-hand circular polarization from low frequency to high frequency; When the third and fifth PIN diodes are in the closed state and the second and fourth PIN diodes are in the open state, the three frequency bands of the antenna are in right-hand circular polarization, right-hand circular polarization and left-hand circular polarization from low frequency to high frequency; When the fourth and fifth PIN diodes are in the closed state and the second and third PIN diodes are in the open state, the three frequency bands of the antenna are all in linear polarization; The microstrip feed line of the input port can change the feed line structure by controlling the state of the first PIN diode to achieve good impedance matching in each polarization state; when the three frequency bands of the antenna are in left-hand circular polarization, left-hand circular polarization and right-hand circular polarization from low frequency to high frequency, the first PIN diode is in an open state; when the three frequency bands of the antenna are in right-hand circular polarization, right-hand circular polarization and left-hand circular polarization from low frequency to high frequency, the first PIN diode is in an open state; when the three frequency bands of the antenna are all in linear polarization, the first PIN diode is in a closed state.

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