A dual-band, high-isolation, compact BeiDou III satellite transceiver antenna

Abstract

The present invention discloses a dual-frequency, high-isolation, compact BeiDou-III satellite transceiver antenna, which relates to the field of satellite communication technology and solves the technical problem of poor isolation between two antennas with similar frequency bands under limited size. The present invention comprises a first antenna, a second antenna and a feed circuit board stacked in sequence from top to bottom, the feed circuit board comprising a three-branch stripline coupler, the three-branch stripline coupler comprising a main coupling line and a secondary coupling line symmetrically arranged, a first branch line, a second branch line and a third branch line being connected between the main coupling line and the secondary coupling line, the left and right ends of the main coupling line being a first port and a third port respectively, and the left and right ends of the secondary coupling line being a second port and a fourth port respectively. The present invention has a targeted design for the transceiver antenna and the feed network, and the BDS L band and BDS B1 radiation patches can be stacked to achieve antenna miniaturization design without affecting antenna performance.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a compact dual-frequency, high-isolation, Beidou-III satellite transceiver integrated antenna. Background Art

[0002] The Beidou satellite navigation system has been widely used in both military and civilian fields. As a key front-end component of the system, the performance of satellite navigation antennas directly impacts the overall system performance. With the continuous advancement of satellite navigation technology, the requirements for satellite navigation antennas are becoming increasingly stringent. Not only must they maintain excellent radiation performance, but they also require miniaturization, multi-band, multi-polarization, and high isolation.

[0003] Currently, satellite communications require simultaneous operation in multiple frequency bands. BeiDou-3 satellites primarily require frequency bands B3, B1, L, S, and B2b. The L antenna is a transmitting antenna with left-hand circular polarization, while the antennas in the remaining frequency bands are receiving antennas with right-hand circular polarization. The B1 receiving band and the L transmitting band of BeiDou-3 satellite antennas are similar (L: 1615.68±4.08MHz, B1: 1575.42±16.368MHz). This results in significant coupling between the antennas, making the B1 receiving band susceptible to interference from L-band transmitted signals when operating simultaneously. To minimize B1 reception performance, existing methods often increase isolation by increasing the distance between antenna elements. However, this increases antenna size, hindering miniaturization requirements. Furthermore, existing B1 receiving antennas and L-band transmitting antennas use independent power feeds, which does not meet the requirements for high integration and miniaturization.

[0004] The lowest frequency of the BeiDou-3 transceiver antenna L is only a few tens of megahertz away from the highest frequency of the antenna B1. When both transmitters and receivers are operating simultaneously, the received signal is often much weaker than the transmitted signal, making it susceptible to interference. In actual products, these antennas are often very limited in size. Conventional designs place two separate antennas parallel to each other at a distance, but this approach is impractical. In existing designs, the antennas can only be stacked, but the isolation between the stacked antenna L and the antenna B1 is only about 10-20dB. Summary of the Invention

[0005] In response to the technical problem of poor isolation between two antennas with similar frequency bands under limited size, this invention proposes a dual-band, high-isolation, compact Beidou-3 satellite transceiver integrated antenna, which can solve the problem that the BDS B1 band is susceptible to interference when the BDS L band and BDS B1 band work at the same time, and can be used in highly integrated and miniaturized devices.

[0006] A dual-band, high-isolation, compact Beidou-III satellite transceiver antenna comprises: a first antenna, a second antenna, and a feed circuit board stacked sequentially from top to bottom; the feed circuit board comprises a three-branch stripline coupler, and the three-branch stripline coupler comprises a symmetrically arranged main coupling line and a secondary coupling line; a first branch line, a second branch line, and a third branch line are connected between the main coupling line and the secondary coupling line; the left and right ends of the main coupling line are a first port and a third port, respectively; and the left and right ends of the secondary coupling line are a second port and a fourth port, respectively.

[0007] Furthermore, the main coupling line and the secondary coupling line have the same length, the first branch line, the second branch line and the third branch line have the same length, and the length of the main coupling line is twice the length of the first branch line.

[0008] Furthermore, when any one of the first port, the second port, the third port and the fourth port is used as an input port, the corresponding port symmetrical to it on the other coupling line serves as an isolation port due to mutual cancellation of electromagnetic waves, and the remaining two ports are output ports.

[0009] Furthermore, the two output ports respectively output signals with equal amplitudes and 90° phase difference, which can form left-hand circularly polarized waves or right-hand circularly polarized waves when transmitted to the first antenna and the second antenna.

[0010] Furthermore, the lengths of the main coupling line and the sub-coupling line are 1 / 2 wavelength, the lengths of the first branch line, the second branch line, and the third branch line are 1 / 4 wavelength, the main coupling line, the sub-coupling line, and the second branch line are arranged between the first branch line and the third branch line, the impedances of the main coupling line, the sub-coupling line, and the second branch line are the same, the impedances of the first branch line and the third branch line are the same, and the impedance of the main coupling line is less than the impedance of the first branch line.

[0011] Furthermore, the feeding circuit board directly feeds the first antenna via a feeding probe, and the second antenna is coupled and fed via the feeding probe.

[0012] Furthermore, the first antenna includes a first dielectric substrate, a first radiation patch arranged on the upper surface of the first dielectric substrate, and a first metal floor arranged on the lower surface of the first dielectric substrate; the second antenna includes a second dielectric substrate, a second radiation patch arranged on the upper surface of the second dielectric substrate, and a second metal floor arranged on the lower surface of the second dielectric substrate.

[0013] Furthermore, the feed circuit board includes a feed probe, which passes through the second metal floor, the second dielectric substrate, the second radiation patch, the first metal floor, and the first dielectric substrate in sequence, and is connected to the first radiation patch. The second radiation patch, the second dielectric substrate, the second metal floor, the first dielectric substrate, and the first metal floor are not in contact with the feed probe. The feed probe transmits the signal directly to the first radiation patch and transmits the signal to the second radiation patch through electromagnetic coupling.

[0014] Furthermore, the first radiation patch and the second radiation patch are both provided with short stubs, and the short stubs are provided at the centers of the four sides of the radiation patches.

[0015] The beneficial effects of the present invention include:

[0016] 1. Miniaturized design of dual-band dual-polarized transceiver antenna. Two antennas with close working frequency bands are easily interfered with each other when placed directly together. For example, the existing BDS L-band and BDS B1 frequency transceiver antennas are only 20MHz apart. In order to shield the interference, the antennas of the two frequency bands are generally set in parallel or separated by antennas with farther working frequency bands. Although the interference is shielded, the antenna size is large and is not suitable for miniaturized platforms. For this reason, the present invention directly stacks the two antennas, and considering that the two antenna bands are close, the feeding between the antennas can be achieved by coupling feeding, thereby reducing the number of feeding ports and the complexity of the feeding network. It can greatly save space in the stacking design. At the same time, it is designed based on the stripline coupler, adds multiple branch lines, and uses multi-path coupling to offset parasitic effects and improve port isolation, thereby achieving antenna miniaturization without affecting antenna performance.

[0017] 2. Design of a miniaturized high-isolation feeding network. The existing BDS L-band and BDS B1 frequency feeding networks use independent feeding networks to achieve left-hand circular polarization and right-hand circular polarization. This method is not conducive to high-integration design and will increase the size of the antenna structure. The present invention is based on the design of a stripline coupler, adding multiple branch lines to achieve frequency band expansion and improved isolation. By designing the operating frequency band of the stripline coupler, the design method of the present invention can be applied to the miniaturization design of dual-band, dual-polarization antennas in other frequency bands.

[0018] 3. Antenna feeding method. The two frequency band antennas share a feeding port, and the upper and lower radiating patches are fed together. The feeding probe passes through the via of the lower patch antenna and is connected to the upper patch antenna. The upper patch antenna is directly fed by the feeding probe, and the lower patch antenna is coupled and fed by the feeding probe. This method reduces the number of feeding ports and the complexity of the feeding network, which can greatly save space in the stacking design and is conducive to product miniaturization. Especially in multi-band applications, two or three frequency bands can be shared. The design method of the present invention can also achieve the purpose by using shared feeding technologies such as single feeding point or multiple feeding points.

[0019] 4. The two antennas share a common feed circuit. Based on the performance of the coupler's four ports, a single coupler is used to excite both antennas, generating two circularly polarized waves with different polarizations. Compared to conventional dual circularly polarized antennas that require two couplers to achieve different polarization modes, the feed circuit of this invention saves dielectric substrate space, making it suitable for miniaturization scenarios. It also simplifies processing complexity and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a two-dimensional structural schematic diagram of a dual-frequency, high-isolation, compact Beidou-III satellite transceiver integrated antenna involved in an embodiment of the present application.

[0021] Figure 2 This is a three-dimensional structural schematic diagram of a dual-band, high-isolation, compact BeiDou-III satellite integrated transceiver antenna involved in an embodiment of the present application.

[0022] Figure 3 Schematic diagram of the structure of a three-branch stripline coupler according to an embodiment of the present application.

[0023] Figure 4 Schematic diagram of a coaxial dual-point probe according to an embodiment of the present application.

[0024] Figure 5 This is a gain diagram of a dual-band, high-isolation, compact BeiDou-III satellite transceiver integrated antenna operating in the L-band, as involved in an embodiment of the present application.

[0025] Figure 6 This is a schematic diagram of the axial ratio of a dual-band, high-isolation, compact BeiDou-III satellite transceiver integrated antenna operating in the L-band, according to an embodiment of the present application.

[0026] Figure 7 This is a gain diagram of a compact dual-band, high-isolation BeiDou-III satellite transceiver integrated antenna operating in the B1 frequency band, according to an embodiment of the present application.

[0027] Figure 8 This is a schematic diagram of the axial ratio of a dual-band, high-isolation, compact BeiDou-3 satellite transceiver integrated antenna operating in the B1 frequency band, according to an embodiment of the present application.

[0028] Figure 9 This is a schematic diagram of the isolation between the two ports of a dual-band, high-isolation, compact BeiDou-III satellite transceiver integrated antenna involved in an embodiment of the present application when operating in the transmit frequency band.

[0029] Attached photos

[0030] 1-first radiation patch, 2-first dielectric substrate, 3-first metal floor, 4-second radiation patch, 5-second dielectric substrate, 6-second metal floor, 71-SMA RF connector of antenna L, 72-SMA RF connector of antenna B1, 8-feed circuit board, 9-three-branch stripline coupler, 10-metal feed pin, 11-screw, 91-first port, 92-second port, 93-third port, 94-fourth port, 95-main coupling line, 96-second coupling line, 97-first branch line, 98-second branch line, 99-third branch line. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0032] The following is combined with Figure 1-2 The specific embodiments of the present invention are described in detail;

[0033] A compact, dual-band, high-isolation BeiDou-3 satellite transceiver antenna incorporates two key technologies: a miniaturized transceiver design and high isolation between transmit and receive signals in adjacent frequency bands. Specifically, in this embodiment, the adjacent frequency bands refer to the L and B1 bands.

[0034] In terms of high isolation design for reception and transmission: the high isolation performance for reception and transmission is achieved through the feed circuit board. The existing 3dB stripline coupler has the problems of relatively low bandwidth and low isolation between ports. The present invention introduces a coupler branch line and expands the branch line into three sections. The bandwidth is widened through a cascade structure. At the same time, multipath coupling is used to offset parasitic effects and improve port isolation. The coupler has a broadband high isolation effect. The output end provides two metal feed pins with signals of the same amplitude and a phase difference of 90°. The input end and isolation end of the coupler are respectively connected to the SMA RF connectors of antenna B1 and antenna L, thereby forming left-handed circularly polarized radiation and right-handed circularly polarized radiation, ensuring that the transmitting and receiving antennas have different polarization modes and good isolation. Specifically, a dual-band high-isolation compact Beidou-3 satellite transceiver integrated antenna adopts a microstrip patch antenna stack to achieve a dual-band design and introduces a 3dB coupler to achieve a dual-circularly polarized high-isolation transceiver antenna. It includes: a first antenna, a second antenna and a feed circuit board 8 stacked in sequence from top to bottom.

[0035] Specifically, the feed circuit board 8 includes a three-branch stripline coupler 9, such as Figure 3 As shown, the three-branch stripline coupler 9 includes a main coupling line 95 and a secondary coupling line 96 that are symmetrically arranged, and a first branch line 97, a second branch line 98, and a third branch line 99 are connected between the main coupling line 95 and the secondary coupling line 96. The left and right ends of the main coupling line 95 are the first port 91 and the third port 93, respectively, and the left and right ends of the secondary coupling line 96 are the second port 92 and the fourth port 94, respectively.

[0036] The distance between the first branch line 97 and the second branch line 98 is equal to the distance between the second branch line 98 and the third branch line 99 .

[0037] When any one of the first port 91 , the second port 92 , the third port 93 and the fourth port 94 is used as an input port, the corresponding port symmetrical to it on the other coupling line serves as an isolation port due to the mutual cancellation of electromagnetic waves, and the remaining two ports are output ports.

[0038] The two output ports respectively output signals with equal amplitude and 90° phase difference, which can form left-hand circularly polarized waves or right-hand circularly polarized waves when transmitted to the first antenna and the second antenna.

[0039] For example, when the first port 91 serves as the input port, the first port 91 is the coupler input port, the second port 92 is the coupler isolation port, the third port 93 is the coupler pass-through port, and the fourth port 94 is the coupler coupling port. Specifically, the lengths of the main coupling line 95 and the secondary coupling line 96 are 1 / 2 wavelength, and the lengths of the first branch line 97, the second branch line 98, and the third branch line 99 are 1 / 4 wavelength. The electromagnetic waves reaching the third port 93 and the fourth port 94 have the same amplitude, but the phase difference is 90 degrees due to the path difference. The electromagnetic waves reaching the second port 92 have two paths. The two signals have the same amplitude, but the phase difference caused by the path difference is 180 degrees. After merging, the electromagnetic waves cancel each other out. Therefore, no signal passes through the second port 92, which serves as an isolation port.

[0040] The three-branch stripline coupler 9 has a high degree of symmetry, and any port can be used as an input port.

[0041] In another embodiment, a miniaturized design utilizes a double-layer microstrip antenna to achieve dual-band, dual-polarization functionality, enabling the antenna to operate at different resonant frequencies in the L-band and B1-band, respectively, and to achieve left-hand circular polarization and right-hand circular polarization. The transceiver antenna comprises a first antenna, a second antenna, and a feed circuit board 8, stacked from top to bottom. The first antenna comprises a first dielectric substrate 2, a first radiating patch 1 disposed on the upper surface of the first dielectric substrate 2, and a first metal floor 3 disposed on the lower surface of the first dielectric substrate 2, operating in the L-band. The second antenna comprises a second dielectric substrate 5, a second radiating patch 4 disposed on the upper surface of the second dielectric substrate 5, and a second metal floor 6 disposed on the lower surface of the second dielectric substrate 5, operating in the B1-band. The first and second radiating patches 1 and 4 are co-fed, with a feed probe connected to the first antenna through a via in the second antenna. The first antenna is directly fed by the feed probe, while the second antenna is coupled to the feed probe. The use of coaxial probe feeding is conducive to miniaturizing the size of the radiating patch; the upper and lower patches adopt a tightly coupled feeding method to realize multi-band feeding of the multi-layer radiating patch, thereby achieving the miniaturization effect of the entire antenna.

[0042] The feeding circuit board 8 directly feeds the first antenna, and the second antenna is fed via a feeding probe coupling.

[0043] The first dielectric substrate 2, the first radiating patch 1 provided on its upper surface, and the first metal floor 3 provided on its lower surface constitute an L antenna. The second dielectric substrate 5, the second radiating patch 4 provided on its upper surface, and the second metal floor 6 provided on its lower surface constitute a B1 antenna. Both the first dielectric substrate 2 and the second dielectric substrate 5 have square structures.

[0044] The feeding circuit board 8 includes a feeding probe, which passes through the second metal floor 6, the second dielectric substrate 5, the second radiating patch 4, the first metal floor 3, and the first dielectric substrate 2 in sequence through a via hole, and is connected to the upper surface of the first radiating patch 1. The size of the via hole is larger than the outer diameter of the feeding probe, so that the second radiating patch 4, the second dielectric substrate 5, the second metal floor 6, the first dielectric substrate 2, and the first metal floor 3 are not in contact with the feeding probe. The feeding probe transmits the signal directly to the first radiating patch 1 and transmits the signal to the second radiating patch 4 through electromagnetic coupling.

[0045] A 2mm-diameter metalized through-hole (PTH) is located in the center of each of the first and second dielectric substrates 2 and 5, as well as the feed circuit board 8. This creates a short-circuit antenna for lightning protection. The diameter of the PTH is adjustable. The antenna is secured to the back of the feed circuit board 8 by screws 11 inserted through the central through-holes of the first radiating patch 1, the first dielectric substrate 2, the first metal floor 3, the second radiating patch 4, the second dielectric substrate 5, the second metal floor 6, and the feed circuit board 8.

[0046] In another embodiment, the feed probe is a coaxial two-point probe, such as Figure 4 As shown, it includes two metal feed pins 10, and the angle formed by the two metal feed pins 10 and the central axis of the dielectric substrate of the feed circuit board 8 is 90°. The second radiation patch 4, the second dielectric substrate 5, the second metal floor 6, the first dielectric substrate 2, and the first metal floor 3 are opened correspondingly at the position where the metal feed pins 10 pass through to avoid contact with the metal feed pins 10.

[0047] In another embodiment, the first antenna is used as the L antenna and the second antenna is used as the B1 antenna. Since the B1 antenna needs to form a right-handed circularly polarized wave and the L antenna needs to form a left-handed circularly polarized wave, the specific ports are defined as follows: the first port 91 is connected to the SMA RF connector 71 of the external antenna L, the second port 92 is connected to the SMA RF connector 72 of the external antenna B1, the third port 93 and the fourth port 94 are respectively connected to the lower ends of two metal feed pins 10, and the upper ends of the metal feed pins 10 are connected to the upper surface of the first radiation patch 1. By designing a high-isolation 3dB coupler, the isolation between the transmit and receive ports can be effectively improved, and a left-handed circularly polarized wave and a right-handed circularly polarized wave are provided respectively, thus realizing a dual-frequency, dual-circularly polarized, high-isolation transmit and receive antenna.

[0048] The size of the first dielectric substrate 2 is 29 mm×29 mm×5 mm, and the size of the second dielectric substrate 5 is 43 mm×43 mm×9 mm. The thicker dielectric substrate is used to improve the antenna gain.

[0049] The dielectric constant of the first dielectric substrate 2 is 16, and the dielectric constant of the second dielectric substrate 5 is 8. The use of high dielectric constant plates is to reduce the size of the antenna and achieve miniaturized design. The use of dielectric plates with different dielectric constants is to make the radiation patch of the lower antenna larger than the dielectric substrate of the upper antenna, so as not to block the radiation patch of the lower antenna and enable it to form effective radiation.

[0050] The length of the main coupling line 95 and the sub-coupling line 96 is 1 / 2 wavelength, the length of the first branch line 97, the second branch line 98 and the third branch line 99 is 1 / 4 wavelength, the second branch line 98 is arranged between the first branch line 97 and the third branch line 99, the impedance of the main coupling line 95, the sub-coupling line 96 and the second branch line 98 is 36.38Ω, and the impedance of the first branch line 97 and the third branch line 99 is 129.96Ω.

[0051] The first radiation patch 1 and the second radiation patch 4 are both provided with short stubs, which are arranged at the centers of the four sides of the radiation patches. Specifically, the first radiation patch 1 is a square structure with a side length of 20.7 mm. The length and width of the short stubs arranged at the first radiation patch 1 are 5 mm and 1.5 mm respectively; the second radiation patch 4 is also a square structure with a side length of 30.4 mm. The length and width of the short stubs arranged at the second radiation patch 4 are 6 mm and 3 mm, which are used for fine-tuning the resonant frequency, with a cutting angle of 2 mm, changing the current path to improve the circular polarization performance, and a circular polarization performance debugging point can be reserved here.

[0052] The four corners of the first radiation patch 1 and the second radiation patch 4 are chamfered by 1 mm.

[0053] Figure 2 The cylinders on the feed circuit board 8 are metalized vias for electromagnetic shielding. The vias on the four sides are for the upper and lower planes to share the same ground (in order to show all the structures in the figure, transparent processing is done).

[0054] The antenna designed in this embodiment is simulated and analyzed, and the results are as follows: Figure 5-8 shown.

[0055] Figure 5 is the gain pattern of the antenna at the center frequency of the L-band. As can be seen from the figure, the normal gain is 6.56dBi and the gain at an elevation angle of 20° is -0.42dBi, which has good radiation gain and low elevation angle performance.

[0056] Figure 6 is the axial ratio radiation pattern of the antenna at the center frequency of the L-band. It can be seen from the figure that the normal axial ratio of the L-band antenna is 0.31dB, which has a good circular polarization effect.

[0057] Figure 7This is the gain pattern of the antenna at the center of the B1 frequency band. As can be seen from the figure, the normal gain is 5.49dBi and the gain at an elevation angle of 20° is -1.20dBi, which has good radiation gain and low elevation angle performance.

[0058] Figure 8 The axial ratio pattern of the antenna at the center frequency of the B1 frequency band is as follows: The normal axial ratio of the B1 frequency band antenna is 0.43dB, which has a good circular polarization effect.

[0059] Figure 9 This is the isolation between the two ports when the antenna operates in the transmit frequency band. As can be seen from the figure, the maximum isolation between the two ports in the transmit frequency band is 43.7dB.

[0060] The above-described embodiments merely represent specific implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection of the present application. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the technical concept of the present application, and all such variations and improvements fall within the scope of protection of the present application.

Claims

1. A dual-band high-isolation compact BeiDou III satellite transceiver antenna, characterized in that: include: A first antenna, a second antenna, and a feed circuit board are stacked sequentially from top to bottom, the feed circuit board comprising a three-branch stripline coupler, the three-branch stripline coupler comprising a main coupling line and a secondary coupling line symmetrically arranged, a first branch line, a second branch line, and a third branch line connected between the main coupling line and the secondary coupling line, the left and right ends of the main coupling line being a first port and a third port respectively, and the left and right ends of the secondary coupling line being a second port and a fourth port respectively; The impedances of the main coupling line, the secondary coupling line, and the second branch line are the same, the impedances of the first branch line and the third branch line are the same, and the impedance of the main coupling line is smaller than the impedance of the first branch line; The first antenna is used as the L antenna, the second antenna is used as the B1 antenna, the impedance of the main coupling line, the secondary coupling line and the second branch line is 36.38Ω, and the impedance of the first branch line and the third branch line is 129.96Ω; The feeding circuit board directly feeds the first antenna via the feeding probe, and the second antenna is coupled and fed via the feeding probe; The first antenna includes a first dielectric substrate, a first radiation patch arranged on the upper surface of the first dielectric substrate, and a first metal floor arranged on the lower surface of the first dielectric substrate. The second antenna includes a second dielectric substrate, a second radiation patch arranged on the upper surface of the second dielectric substrate, and a second metal floor arranged on the lower surface of the second dielectric substrate.

2. The dual-frequency, high-isolation, compact BeiDou III satellite transceiver antenna according to claim 1, characterized in that: The main coupling line and the auxiliary coupling line have the same length, the first branch line, the second branch line and the third branch line have the same length, and the length of the main coupling line is twice that of the first branch line.

3. The dual-frequency, high-isolation, compact BeiDou III satellite transceiver antenna according to claim 2, characterized in that: When any one of the first port, the second port, the third port and the fourth port is used as an input port, the corresponding port symmetrical to it on the other coupling line serves as an isolation port due to the mutual cancellation of electromagnetic waves, and the remaining two ports are output ports.

4. The dual-frequency, high-isolation, compact BeiDou III satellite transceiver antenna according to claim 3, characterized in that: The two output ports respectively output signals with equal amplitude and 90° phase difference, which can form left-hand circularly polarized waves or right-hand circularly polarized waves when transmitted to the first antenna and the second antenna.

5. The dual-frequency, high-isolation, compact BeiDou III satellite transceiver antenna according to claim 2, characterized in that: The lengths of the main coupling line and the auxiliary coupling line are half a wavelength, the lengths of the first branch line, the second branch line and the third branch line are a quarter wavelength, and the main coupling line, the auxiliary coupling line and the second branch line are arranged between the first branch line and the third branch line.

6. The dual-frequency, high-isolation, compact BeiDou III satellite transceiver antenna according to claim 1, characterized in that: The feed circuit board includes a feed probe, which passes through the second metal floor, the second dielectric substrate, the second radiation patch, the first metal floor, and the first dielectric substrate in sequence, and is connected to the first radiation patch. The second radiation patch, the second dielectric substrate, the second metal floor, the first dielectric substrate, and the first metal floor are not in contact with the feed probe. The feed probe directly transmits the signal to the first radiation patch and transmits the signal to the second radiation patch through electromagnetic coupling.

7. The dual-frequency, high-isolation, compact BeiDou III satellite transceiver antenna according to claim 1, characterized in that: The first radiation patch and the second radiation patch are both provided with short stubs, and the short stubs are provided at the centers of the four sides of the radiation patch.

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