Ultra-wideband full-polarization reconfigurable array antenna

Abstract

The application discloses an ultra-wideband full-polarization reconfigurable array antenna, comprising a cross-shaped array antenna composed of two Vivaldi array antennas arranged orthogically along an X axis and a Y axis and a reconfigurable feed network, the two being connected through a coaxial line, and the feed phase of the two orthogical Vivaldi array antennas being adjusted through the feed network to realize the regulation and control of the polarization mode. The application adopts two tightly-coupled Vivaldi array antennas arranged in a cross shape as radiators, designs a reconfigurable feed network to provide an input phase difference, and realizes the ultra-wideband polarization reconfiguration. The application solves the problems of the existing polarization reconfigurable array antenna, such as narrow working bandwidth, low gain and few polarization states, and provides a new idea for the design of the ultra-wideband full-polarization reconfigurable array antenna.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to an ultra-wideband fully polarized reconfigurable array antenna. Background Technology

[0002] Electromagnetic fields are vector fields. Electromagnetic waves in free space exhibit three polarization modes: linear polarization, circular polarization, and elliptic polarization. Circularly polarized waves are further divided into left-handed and right-handed circularly polarized waves. Antennas capable of emitting two or more polarizations are called polarization-reconfigurable antennas. Based on the polarization of the electromagnetic waves emitted, antennas are classified as linearly polarized antennas and circularly polarized antennas. Antennas capable of simultaneously achieving both linear and circular polarization are called fully polarization-reconfigurable antennas. Fully polarization-reconfigurable array antennas are based on traditional array antennas. By modifying the antenna element structure, feed network design, and antenna arrangement, the array antenna can dynamically adjust its characteristics according to system requirements and the operating environment, achieving switching between linear and circular polarization modes. While there has been considerable research on polarization-reconfigurable antennas, current applications generally suffer from low antenna gain, narrow bandwidth, and a limited number of achievable polarization states. Research on ultra-wideband fully polarization-reconfigurable array antennas remains of profound significance.

[0003] In free space, any polarized wave can be decomposed into two orthogonal linearly polarized waves. Reflected in an antenna, this translates to a circularly polarized antenna, which can be composed of two spatially orthogonal linearly polarized antennas with a 90° phase difference in their feeds. For example, application 202211055816.5 describes connecting two vertical butterfly dipole antennas on a dielectric substrate. A coaxial feed line is connected to two phase shifters via diodes to feed the center of the antenna element. Phase changes are controlled by switching the diodes on and off, thus achieving the reconfiguration function of left-hand and right-hand circular polarization. This application describes a four-element array antenna. Another example is application 202210141900.2, which uses a circular ring antenna as the radiator. Three feed ports are evenly distributed on the ring antenna, and a high-impedance surface composed of a fan-shaped patch and a metal ground plane replaces the metal reflector at the bottom. Switching between linear and circular polarization is achieved by changing the amplitude and phase of the three ports. This patent describes a single antenna.

[0004] In application 202211055816.5, the antenna operates in the 1.6-2.4GHz frequency band, which does not meet the requirements for ultra-wideband operation. Furthermore, it can only achieve polarization reconfiguration between left-hand and right-hand circular polarization, resulting in a limited number of polarization states. In application 202210141900.2, the antenna polarization state is determined by the phase and amplitude of the feed port, requiring an additional phase-shifting structure. Moreover, the antenna in this application operates in the 3.26-3.68GHz frequency band, resulting in a narrow operating bandwidth. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an ultra-wideband fully polarizable reconfigurable array antenna that uses a tightly coupled Vivaldi array antenna and an ultra-wideband microstrip phase shifter to achieve three polarization modes: left-hand circular polarization, right-hand circular polarization, and linear polarization.

[0006] To address the aforementioned technical problems, this invention provides an ultra-wideband fully polarized reconfigurable array antenna, comprising: a cross-shaped array antenna composed of two Vivaldi array antennas orthogonally placed along the X-axis and Y-axis, and a reconfigurable feed network, which are connected by a coaxial line. The polarization mode is controlled by adjusting the feed phase of the two orthogonal Vivaldi array antennas through the feed network.

[0007] Preferably, the two orthogonal Vivaldi array antennas are six-element Vivaldi array antennas. The six-element Vivaldi array antenna includes six Vivaldi antenna elements, which are numbered from left to right as elements 1 to 6. Elements 2, 3, 4, and 5 are the working elements, while the outer elements 1 and 6 are set as virtual elements that are not connected to the excitation and are used for impedance matching.

[0008] Preferably, the six-element Vivaldi array antenna is divided into three elements on each side from the middle and connected by metal pillars. Two 1-to-2 power dividers are used to feed the left and right three elements respectively. The 1-to-2 power dividers are fifth-order Wilkinson power dividers.

[0009] Preferably, the six-element Vivaldi array antennas, arranged in a cross shape along the X-axis and Y-axis, are connected to the same metal column.

[0010] Preferably, the reconfigurable power supply network includes three fifth-order Wilkinson power dividers, four PIN diode SPDTs, two ultra-wideband microstrip phase shifters, a dielectric substrate, and a metal ground plane; the fifth-order Wilkinson power dividers, PIN diode SPDTs, and ultra-wideband microstrip phase shifters are located on the front surface of the dielectric substrate, and the metal ground plane is located on the back surface of the dielectric substrate.

[0011] Preferably, the PIN diode SPDT consists of two PIN diodes placed in the same direction and has a single-pole double-throw switch function. The state of the PIN diode SPDT is switched by adjusting the bias voltage of the PIN diodes.

[0012] Preferably, the ultra-wideband microstrip phase shifter includes a reference microstrip line and a phase-shifting microstrip structure. The double-throw terminal of the PIN diode SPDT is connected to the reference microstrip line and the phase-shifting microstrip structure, respectively. The output phase of the reconfigurable feed network is changed by changing the state of the PIN diode SPDT.

[0013] Preferably, the ultra-wideband microstrip phase shifter is a five-section cascaded impedance transformer and two short-circuit stubs.

[0014] Preferably, the reconfigurable feed network is a five-port network, with the first port of the feed network as the input terminal, and the second, third, fourth, and fifth ports of the feed network as output terminals. The output signals of the second and third ports of the feed network are of equal amplitude and in phase, and the output signals of the fourth and fifth ports of the feed network are of equal amplitude and in phase. The output phase difference of the second, third, fourth, and fifth ports of the feed network is changed by changing the state of the PIN diode SPDT. The second port of the feed network is connected to the first port of the antenna, the third port of the feed network is connected to the second port of the antenna, the fourth port of the feed network is connected to the third port of the antenna, and the fifth port of the feed network is connected to the fourth port of the antenna.

[0015] Preferably, by changing the output phase of the reconfigurable feed network, the synthesis method of the antenna radiation field is changed, thereby switching the polarization mode of the ultra-wideband fully polarized reconfigurable array antenna. The polarization mode includes three polarization modes: left-hand circular polarization, right-hand circular polarization, and linear polarization with an angle of 45° with the negative half-axis of the X-axis. When two orthogonal Vivaldi array antennas are excited with equal amplitude and in phase, the array antennas operate with linear polarization with an angle of 45° with the negative X-axis. When two orthogonal Vivaldi array antennas are excited with a phase difference of +90°, the array antennas operate with left-hand circular polarization. When two Vivaldi array antennas are excited with a phase difference of -90°, the array antennas operate with right-hand circular polarization.

[0016] The beneficial effects of this invention are as follows: it uses two tightly coupled Vivaldi array antennas arranged in a cross shape as radiators, and designs a reconfigurable feed network to provide the input phase difference, thereby realizing ultra-wideband polarization reconfigurability; this invention solves the problems of narrow operating bandwidth, low gain, and few polarization states of existing polarization reconfigurable array antennas, and provides a new idea for the design of ultra-wideband fully polarization reconfigurable array antennas. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the three-dimensional structure of the antenna of the present invention.

[0018] Figure 2 For the present invention Figure 1 Top view of the XOY plane.

[0019] Figure 3 This is a schematic diagram of the reconfigurable part of the reconfigurable power supply network of the present invention.

[0020] Figure 4 For the present invention Figure 1 The front view of the YOZ plane.

[0021] Figure 5 For the present invention Figure 1 Rear view of the YOZ plane.

[0022] Figure 6 This is a graph showing the reflection coefficient of the antenna of the present invention operating with the linear polarization described above.

[0023] Figure 7 This is a gain curve of the antenna of the present invention operating with the linear polarization described above.

[0024] Figure 8(a) shows the radiation pattern of the E-plane at 3 GHz when the antenna of the present invention is operating with the linear polarization described above.

[0025] Figure 8(b) shows the H-plane radiation pattern of the antenna of the present invention at 3 GHz when it operates with the linear polarization described above.

[0026] Figure 9(a) shows the radiation pattern of the E-plane at 7 GHz when the antenna of the present invention is operating with the linear polarization described above.

[0027] Figure 9(b) shows the H-plane radiation pattern of the antenna of the present invention at 7 GHz when it operates with the linear polarization described above.

[0028] Figure 10(a) shows the radiation pattern of the antenna of the present invention in the E-plane at 11 GHz when it operates with the linear polarization described above.

[0029] Figure 10(b) shows the H-plane radiation pattern of the antenna of the present invention at 11 GHz when it operates with the linear polarization described above.

[0030] Figure 11 This is a graph showing the reflection coefficient of the antenna of the present invention when it operates in circular polarization.

[0031] Figure 12 This is a gain curve of the antenna of the present invention when it operates in circular polarization.

[0032] Figure 13(a) shows the radiation pattern of the XOZ plane at 3 GHz when the antenna of the present invention is operating with the left-hand circular polarization.

[0033] Figure 13(b) shows the radiation pattern of the antenna of the present invention in the YOZ plane at 3 GHz when it operates with the left-hand circular polarization.

[0034] Figure 14(a) shows the radiation pattern of the XOZ plane at 7 GHz when the antenna of the present invention is operating with the left-hand circular polarization.

[0035] Figure 14(b) shows the radiation pattern of the antenna of the present invention in the YOZ plane at 7 GHz when it operates with the left-hand circular polarization.

[0036] Figure 15(a) shows the radiation pattern of the XOZ plane at 11 GHz when the antenna of the present invention is operating with the left-hand circular polarization.

[0037] Figure 15(b) shows the radiation pattern of the antenna of the present invention in the YOZ plane at 11 GHz when it operates with the left-hand circular polarization.

[0038] Figure 16 This is the axial ratio diagram of the antenna of the present invention at 3 GHz when it operates with the left-hand circular polarization.

[0039] Figure 17 This is the axial ratio diagram of the antenna of the present invention at 7 GHz when it operates with the left-hand circular polarization.

[0040] Figure 18 This is the axial ratio diagram of the antenna of the present invention at 11 GHz when it operates with the left-hand circular polarization. Detailed Implementation

[0041] like Figure 1 As shown, an ultra-wideband fully polarized reconfigurable array antenna includes: a cross-shaped array antenna and a reconfigurable feed network. The cross-shaped array antenna consists of two six-element Vivaldi array antennas arranged along the X-axis and Y-axis.

[0042] like Figure 2 As shown, the reconfigurable feed network is a five-port network, where the first port 1-1 of the feed network serves as the signal input terminal. The second port 1-2 and the third port 1-3 of the feed network are connected to the first port 2-1 and the second port 2-2 of the array antennas placed along the X-axis in the cross-shaped array antenna using coaxial cables. The fourth port 1-4 and the fifth port 1-5 of the feed network are connected to the third port 2-3 and the fourth port 2-4 of the array antennas placed along the Y-axis in the cross-shaped array antenna using coaxial cables. The array antennas placed along the Y-axis and the array antennas placed along the X-axis are connected by metal posts 2-5. All port structures have SMA connectors whose inner conductors are connected to microstrip transmission lines. Specifically, the outer conductors of the SMA connectors of the first port 1-1, the second port 1-2, the third port 1-3, the fourth port 1-4, and the fifth port 1-5 are connected to the metal ground plane 1-7. The outer conductors of the SMA connectors of the first antenna port 2-1, the second antenna port 2-2, the third antenna port 2-3, and the fourth antenna port 2-4 are connected to the antenna ground plane 2-10.

[0043] A reconfigurable feed network is printed on the upper layer of dielectric substrate 1-6, and the lower layer of dielectric substrate 1-6 is a metal ground plane 1-7. Dielectric substrate 1-6 is made of F4BM220, with a dielectric constant of 2.2 and a thickness of 0.55 mm. The signal is input to the reconfigurable feed network through the first port 1-1 of the feed network, and is divided into two signals by a fifth-order Wilkinson power divider 1-8. One signal, along the positive Y-axis, passes through isolation capacitor 1-11-1 and connects to PIN diode SPDT1-11, which in turn connects to the ultra-wideband microstrip phase shifter 1-15. (The text repeats itself here.) Figure 3As shown, the PIN diode SPDT1-11 is composed of an isolation capacitor 1-11-1, a square microstrip patch 1-11-2, PIN diodes 1-11-3 and 1-11-4, an isolation inductor 1-1-5, a load resistor 1-11-6, and a metal pad 1-11-7. PIN diodes 1-11-3 and 1-11-4 are placed in the same direction. A DC bias current is applied to the square patch 1-11-2, which is connected to both PIN diodes 1-11-3 and 1-11-4, through a DC bias circuit composed of the isolation inductor 1-11-5, the load resistor 1-11-6, and the metal pad 1-11-7. This controls the conduction of either PIN diode 1-11-3 or PIN diode 1-11-4. When one of them is conducting, the other PIN diode is in the off state, thus realizing the single-pole double-throw function. When PIN diode 1-11-3 is on and PIN diode 1-11-4 is off, PIN diode SPDT1-11 connects to the phase-shifting structure of the ultra-wideband microstrip phase shifter. The phase-shifting structure consists of a first impedance transformer 1-15-1 connected to a short-circuit stub 1-15-2 and a second impedance transformer 1-15-4. The end of the short-circuit stub 1-15-2 is connected to a metal ground plane 1-7 via a ground via 1-15-3, forming a short circuit. The second impedance transformer 1-15-4 is connected to a third impedance transformer 1-15-5, and the ultra-wideband microstrip phase shifter structure is symmetrical about a line parallel to the X-axis passing through the geometric center of the third impedance transformer 1-15-5. When PIN diode 1-11-3 is off and PIN diode 1-11-4 is on, the signal passes through the reference microstrip line structure of the ultra-wideband microstrip phase shifter. The reference microstrip line structure includes a 50Ω microstrip line 1-15-6 and a PIN diode 1-15-7. PIN diode 1-15-7 is placed in the same direction as PIN diode 1-11-4, and their on / off states are identical. When PIN diode 1-15-7 is on, current flows normally; when PIN diode 1-15-7 is off, the 50Ω microstrip line is cut off, thereby suppressing high-frequency current on the microstrip line and expanding the high-frequency bandwidth. PIN diode SPDT1-12 is located symmetrically to PIN diode SPDT1-11. PIN diode SPDT1-11 and PIN diode SPDT1-12 operate in opposite states and are connected to the same microstrip structure. After passing through PIN diode SPDT1-12, the signal is output from the second port 1-2 and the third port 1-3 of the feed grid via a fifth-order Wilkinson power divider 1-9.The reconfigurable power supply network is symmetrical about a straight line parallel to the X-axis passing through its geometric center. Specifically, fifth-order Wilkinson power dividers 1-9 and 1-10 are symmetrical about the straight line; PIN diodes SPDT1-11, SPDT1-12, SPDT1-13, and SPDT1-14 are symmetrical about the straight line; and ultra-wideband microstrip phase shifters 1-15 and 1-16 are symmetrical about the straight line.

[0044] like Figure 4 and Figure 5 As shown, the cross-shaped array antenna is a four-port device. The Vivaldi array antenna, positioned along the Y-axis, is fed through the antenna's third feed port 2-3 and fourth feed port 2-4. Taking the antenna's third port 2-3 as an example, the signal is transmitted through a fifth-order Wilkinson power divider 2-7 to sector-feed baluns 2-8 and 2-9, and then coupled by sector-feed baluns 2-8 and 2-9 to an exponential curve radiating arm 2-11 located on the back of the antenna dielectric substrate 2-6, where it is converted into electromagnetic waves and radiated outwards. The exponential curve radiating arm 2-11 is connected to the antenna ground plane 2-10.

[0045] When PIN diodes SPDT1-11, SPDT1-12, SPDT1-13, and SPDT1-14 are all connected to the reference microstrip line of the ultra-wideband microstrip phase shifter, the output phases of feed network second port 1-2, feed network third port 1-3, feed network fourth port 1-4, and feed network fifth port 1-5 are the same, and the ultra-wideband fully polarized reconfigurable array antenna operates in a linear polarization mode with a 45° angle to the negative half-axis of the X-axis; when PIN diodes SPDT1-11 and SPDT1-12 are connected to the phase shifting structure of ultra-wideband microstrip phase shifter 1-15, and PIN diodes SPDT1-13 and SPDT1-14 are connected to the reference microstrip line of ultra-wideband microstrip phase shifter 1-16, the output phase difference between feed network second port 1-2, feed network third port 1-3 and feed network fourth port 1-4, and feed network fifth port 1-5 is +90°, that is, the antenna... When the input phase of the first port 2-1 and the second port 2-2 of the antenna leads the input phase of the third port 2-3 and the fourth port 2-4 of the antenna by 90°, the ultra-wideband fully polarized reconfigurable array antenna operates in a left-hand circular polarization mode. When the PIN diodes SPDT1-11 and SPDT1-12 are connected to the reference microstrip line of the ultra-wideband microstrip phase shifter 1-15, and the PIN diodes SPDT1-13 and SPDT1-14 are connected to the phase shifting structure of the ultra-wideband microstrip phase shifter 1-16, the output phase difference between the second port 1-2 and the third port 1-3 of the feed network and the fourth port 1-4 and the fifth port 1-5 of the feed network is -90°, that is, the input phase of the first port 2-1 and the second port 2-2 of the antenna lags the input phase of the third port 2-3 and the fourth port 2-4 of the antenna by 90°, the ultra-wideband fully polarized reconfigurable array antenna operates in a right-hand circular polarization mode.

[0046] Figure 6 The graph shows the reflection coefficient of the ultra-wideband fully polarized reconfigurable array antenna in the linear polarization configuration according to an embodiment of the present invention. As can be seen from the graph, the linear polarization operating bandwidth of the ultra-wideband fully polarized reconfigurable array antenna is 2.1-12.5 GHz, reaching a 5.95-fold bandwidth, and the relative bandwidth is 142%.

[0047] Figure 7 The figure shows the gain curve of the ultra-wideband fully polarized reconfigurable array antenna in the linear polarization according to an embodiment of the present invention. As can be seen from the figure, the gain of the ultra-wideband fully polarized reconfigurable array antenna in linear polarization is 3.79-16.4 dBi.

[0048] Figures 8(a), 8(b), 9(a), 9(b), 10(a), and 10(b) are the radiation patterns of the E-plane and H-plane of the ultra-wideband fully polarized reconfigurable array antenna of the present invention when it operates with the linear polarization at three frequency points of 3 GHz, 7 GHz, and 11 GHz. As can be seen from the figures, the antenna has a good cross-polarization suppression ratio in the main beam direction.

[0049] Figure 11 The graph shows the reflection coefficient curve of the ultra-wideband fully polarized reconfigurable array antenna in circular polarization according to an embodiment of the present invention. As can be seen from the graph, the circular polarization operating bandwidth of the ultra-wideband fully polarized reconfigurable array antenna is 2.77-12.2 GHz, reaching a 4.4-fold bandwidth, and the relative bandwidth is 125%.

[0050] Figure 12 The figure shows the gain curve of the ultra-wideband fully polarized reconfigurable array antenna in circular polarization according to an embodiment of the present invention. As can be seen from the figure, the gain of the ultra-wideband fully polarized reconfigurable array antenna in circular polarization is 6.87-15.9 dBi.

[0051] Figures 13(a), 13(b), 14(a), 14(b), 15(a), and 15(b) are the radiation patterns of the XOZ and YOZ planes of the ultra-wideband fully polarized reconfigurable array antenna of the present invention when operating at three frequency points of 3 GHz, 7 GHz, and 11 GHz with the left-hand circular polarization, respectively. As can be seen from the figures, the antenna has a good cross-polarization suppression ratio in the main beam direction, and the difference between the main polarization and the cross-polarization is more than 20 dB.

[0052] Figure 16 , Figure 17 , Figure 18 The figures show the antenna axial ratio diagrams of the ultra-wideband fully polarized reconfigurable array antenna of the present invention when it operates in the left-hand circular polarization at three frequency points of 3GHz, 7GHz, and 11GHz. It can be seen from the figures that the 3dB axial ratio beamwidth of the antenna decreases as the operating frequency increases.

[0053] Since the array antenna and reconfigurable feed network in this embodiment are both designed symmetrically, and the right-hand circular polarization working state of the ultra-wideband fully polarized reconfigurable array antenna is similar to the left-hand circular polarization working state mentioned above, the simulation results of its right-hand circular polarization working state are not given.

[0054] In summary, this invention provides an ultra-wideband fully polarized reconfigurable array antenna. It employs two tightly coupled Vivaldi array antennas arranged in a cross shape as radiators, and designs a reconfigurable feed network to provide the input phase difference, achieving ultra-wideband polarization reconfigurability. Its linear polarization operates with a bandwidth of 2.1-12.5 GHz, reaching a 5.95-fold harmonic bandwidth, with a relative bandwidth of 142%, and an antenna gain of 3.79-16.4 dBi. The difference between coplanar polarization and cross-polarization in the main beam direction is greater than 20 dB. Its circular polarization operates with a bandwidth of 2.77-12.2 GHz, reaching a 4.4-fold harmonic bandwidth, with a relative bandwidth of 126%, and an antenna gain of 6.87-15.9 dBi. The 3 dB axial ratio beamwidth decreases with increasing frequency, and the difference between main polarization and cross-polarization in the main beam direction is greater than 20 dB. This invention solves the problems of narrow operating bandwidth, low gain, and limited polarization states in existing polarization reconfigurable array antennas, providing a new approach for the design of ultra-wideband fully polarized reconfigurable array antennas.

Claims

1. An ultra-wideband fully polarized reconfigurable array antenna, characterized in that, include: A cross-shaped array antenna consisting of two Vivaldi array antennas orthogonally placed along the X-axis and Y-axis, and a reconfigurable feed network, are connected by a coaxial line. The polarization mode can be controlled by adjusting the feed phase of the two orthogonal Vivaldi array antennas through the reconfigurable feed network. The two orthogonal Vivaldi array antennas are six-element Vivaldi array antennas. The six-element Vivaldi array antennas include six Vivaldi antenna elements, which are numbered 1 to 6 from left to right. Among them, elements 2, 3, 4, and 5 are the working elements, while the outer elements 1 and 6 are set as virtual elements that are not connected to the excitation and are used for impedance matching. The six-element Vivaldi array antenna is divided into three elements on the left and three on the right from the middle and connected by metal pillars. It uses two 1-to-2 power dividers to feed the left and right three elements respectively. The 1-to-2 power dividers are fifth-order Wilkinson power dividers. The reconfigurable power supply network is a five-port network, with the first port as the input and the second, third, fourth, and fifth ports as outputs. The signal enters the reconfigurable power supply network through the first port and is divided into two signals by a first fifth-order Wilkinson power divider. One signal passes along the positive Y-axis, through the first isolation capacitor, into the first PIN diode SPDT, and then into the first ultra-wideband microstrip phase shifter. After passing through the second PIN diode SPDT, it passes through the second fifth-order Wilkinson power divider and is output from the second and third ports. The other signal passes along the negative Y-axis, through the second isolation capacitor, into the third PIN diode SPDT, and then into the second ultra-wideband microstrip phase shifter. After passing through the fourth PIN diode SPDT, it passes through the third fifth-order Wilkinson power divider and is output from the fourth and fifth ports. The ultra-wideband microstrip phase shifter includes a reference microstrip line and a phase-shifting microstrip structure. The double-throw terminals of the PIN diode SPDT are connected to the reference microstrip line and the phase-shifting microstrip structure, respectively. The output phase of the reconfigurable feed network can be changed by changing the state of the PIN diode SPDT.

2. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 1, characterized in that, The first PIN diode SPDT consists of a first isolation capacitor, a square microstrip patch, a first PIN diode, a second PIN diode, an isolation inductor, a load resistor, and metal pads. The first PIN diode and the second PIN diode are placed in the same direction. A DC bias current is applied to the square patch connected to both the first PIN diode and the second PIN diode through a DC bias circuit composed of an isolation inductor, a load resistor, and metal pads, thereby controlling the conduction of either the first PIN diode or the second PIN diode. When one of them is conducting, the other PIN diode is in the off state, thus realizing the single-pole double-throw function.

3. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 2, characterized in that, When the first PIN diode is turned on and the second PIN diode is turned off, the first PIN diode SPDT is connected to the phase shifting structure of the ultra-wideband microstrip phase shifter. The phase shifting structure consists of a first impedance transformer connected to a short-circuit stub and a second impedance transformer. The end of the short-circuit stub is connected to the metal ground plane through a ground via to form a short circuit. The second impedance transformer is connected to the third impedance transformer. The ultra-wideband microstrip phase shifter structure is symmetrical about a straight line parallel to the X-axis passing through the geometric center of the third impedance transformer. When the first PIN diode is off, and the second PIN diode is on, the signal passes through the reference microstrip line structure of the first ultra-wideband microstrip phase shifter; the reference microstrip line structure includes 50 The microstrip line and the third PIN diode are arranged in the same direction as the second PIN diode, and their on / off states are the same. When the third PIN diode is on, current flows normally; when the third PIN diode is off, 50°C current flows out. The microstrip line is truncated to suppress high-frequency currents on the microstrip line and extend the high-frequency bandwidth.

4. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 1, characterized in that, The six-element Vivaldi array antennas, arranged in a cross shape along the X-axis and Y-axis, are connected to the same metal column.

5. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 1, characterized in that, The PIN diode SPDT consists of two PIN diodes placed in the same direction and has a single-pole double-throw switch function. The state of the PIN diode SPDT is switched by adjusting the bias voltage of the PIN diodes.

6. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 1, characterized in that, The ultra-wideband microstrip phase shifter consists of a five-section cascaded impedance transformer and two short-circuit stubs.

7. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 1, characterized in that, The output signals of the second and third ports are in phase and have the same amplitude. The output signals of the fourth and fifth ports of the feed network are in phase and have the same amplitude. The output phase difference of the second, third, fourth and fifth ports is changed by changing the state of the PIN diode SPDT. The second port is connected to the first port of the antenna, the third port is connected to the second port of the antenna, the fourth port is connected to the third port of the antenna, and the fifth port is connected to the fourth port of the antenna.

8. The ultra-wideband fully polarized reconfigurable array antenna as described in claim 7, characterized in that, By changing the output phase of the reconfigurable feed network, the synthesis method of the antenna radiation field is altered, thereby switching the polarization mode of the ultra-wideband fully polarized reconfigurable array antenna. Polarization modes include left-hand circular polarization, right-hand circular polarization, and polarization along a 45° angle with the negative X-axis. The three polarization modes of linear polarization; when two orthogonal Vivaldi array antennas are excited with equal amplitude and in phase, the array antennas rotate at a 45° angle to the negative X-axis. Angular directional polarization operation; when the phase difference of two orthogonal Vivaldi array antennas is +90°... During excitation, the array antenna operates in a left-hand circular polarization mode; When the phase difference between the two Vivaldi array antennas is -90° When excited, the array antenna operates in a right-hand circular polarization mode.

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