A full-duplex antenna based on gap-coupled differential feed

Abstract

The application discloses a kind of full duplex antennas based on slot coupling differential feed, including two pairs of butterfly dipole antennas, first dielectric plate, four groups of vertically placed signal transmission lines, metal floor, second dielectric plate, two U-shaped feed networks and third dielectric plate;The application is placed on the upper surface and lower surface of first dielectric plate by setting two pairs of butterfly dipole antennas, to radiate horizontal polarization and vertical polarization wave, in order to generate differential signal, four T-shaped slots with the same size are etched on the metal floor, then the differential signal at T-shaped slot is transmitted to the feed position of dipole antenna by four groups of vertically placed transmission lines, and the two U-shaped feed networks are placed vertically without dielectric layer, so as to obtain larger port isolation, which can be applied to simultaneous same frequency full duplex communication system, and wireless signals can be transmitted and received simultaneously at the same frequency, thereby improving spectrum utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a full-duplex antenna based on slot-coupled differential feeding. Background Technology

[0002] Currently, available spectrum resources are very limited. With the rapid development of wireless communication, these resources are becoming increasingly congested, making improving spectrum utilization a key research topic. Most current wireless communication systems are terminals that both transmit and receive signals (e.g., base stations, relays, and mobile terminals). These systems are mostly time-division or frequency-division duplex systems, meaning that these terminals transmit and receive signals at different times or frequency bands, which restricts the rapid development and application of wireless communication. Simultaneous full-duplex communication, operating on the same frequency, offers a solution to improve spectrum resource utilization efficiency and is one of the key technologies for future wireless communication. Summary of the Invention

[0003] The purpose of this invention is to provide a full-duplex antenna based on slot-coupled differential feeding, which can simultaneously transmit and receive wireless signals at the same frequency, thereby improving spectrum utilization efficiency.

[0004] The technical solution adopted in this invention is as follows:

[0005] A full-duplex antenna based on slot-coupled differential feeding includes two pairs of butterfly dipole antennas, a first dielectric substrate, four sets of vertically placed signal transmission lines, a metal ground plane, a second dielectric substrate, two U-shaped feed networks, and a third dielectric substrate.

[0006] The two pairs of butterfly dipole antennas are respectively disposed on the upper and lower surfaces of the first dielectric substrate, and the two pairs of butterfly dipole antennas are placed perpendicular to each other to form a mutually perpendicular dual-polarization radiation mode.

[0007] The second dielectric substrate is disposed below the first dielectric substrate, and the metal ground plate is located on the lower surface of the second dielectric substrate. The metal ground plate has four identical T-shaped slots, which are symmetrically distributed about the center of the metal ground plate, and the vertical parts of the four T-shaped slots are arranged concentrically. The spacing between a pair of opposite T-shaped slots is set to g2. The two pairs of butterfly dipole antennas are arranged corresponding to the four identical T-shaped slots through four sets of vertically placed signal transmission lines.

[0008] The third dielectric plate is disposed below the metal floor, and the two U-shaped power supply networks are respectively located on the upper surface of the second dielectric plate and the lower surface of the third dielectric plate; in the vertical angle from top to bottom, the two ends of one U-shaped power supply network are respectively perpendicularly intersecting the two long parts of one pair of T-shaped slots arranged opposite each other, and the two ends of the other U-shaped power supply network are respectively perpendicularly intersecting the two long parts of another pair of T-shaped slots arranged opposite each other.

[0009] The butterfly dipole antenna is composed of a pair of symmetrically placed trapezoidal metal patches, with the smaller ends facing each other, and the gap between the two metal patches is set as g1.

[0010] It also includes a parasitic metal strip, which is used to connect two metal patches that are facing each other.

[0011] The metal parasitic band includes a first metal narrow band, a second metal narrow band, and two elliptical metal plates. The first metal narrow band and the second metal narrow band are respectively arranged in parallel and symmetrically on two metal plates, and the two ends are respectively connected by two elliptical metal plates.

[0012] It also includes a metal reflector cavity, which is located below the third dielectric substrate, i.e., at the bottom of the antenna. The metal reflector cavity is composed of a box structure without a cover, which is used to increase the far-field radiation gain of the antenna.

[0013] The signal transmission line is divided into multiple segments from top to bottom, with each segment having a different width; this is used to match the required impedance.

[0014] The U-shaped power supply network includes a first microstrip feeder, a second microstrip feeder, a third microstrip feeder, and a fourth microstrip feeder. The midpoint of the second microstrip feeder is perpendicularly and fixedly connected to one end of the first microstrip feeder. The third and fourth microstrip feeders are respectively parallel and symmetrically arranged at both ends of the second microstrip feeder. The third and fourth microstrip feeders have the same structural size. The other end of the first microstrip feeder is used to connect to the power supply port.

[0015] The metal reflective cavity is located below the third dielectric plate and includes a horizontally placed first metal plate and a second, third, fourth, and fifth metal plate vertically surrounding the first metal plate. The second, third, fourth, and fifth metal plates are of the same size and have a height of 5 mm. The distance between the bottom of the metal reflective cavity and the third dielectric plate is 5 mm.

[0016] The T-shaped gap consists of a first gap and a second gap placed perpendicular to the first gap.

[0017] The third and fourth microstrip lines that make up the U-shaped feed network are placed below the second slot that makes up the T-shaped slot, and the length of the third and fourth microstrip lines extending out of the second slot is set to 6 mm.

[0018] This invention uses two pairs of butterfly dipole antennas placed perpendicularly to each other on the upper and lower surfaces of a first dielectric substrate to radiate horizontally and vertically polarized waves. To generate differential signals, four identical T-shaped slots are etched into a metal floor. Four sets of vertically placed transmission lines transmit the differential signals from the T-shaped slots to the feed positions of the dipole antennas. Two U-shaped feed networks are placed on different dielectric layers and perpendicular to each other, thereby achieving a large port isolation. This invention can be applied to simultaneous full-duplex communication systems on the same frequency, allowing simultaneous transmission and reception of wireless signals on the same frequency, thus improving spectrum utilization efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0021] Figure 2 This is a side sectional view of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the butterfly dipole described in this invention;

[0023] Figure 4 This is a schematic diagram of the structure of the metal floor described in this invention;

[0024] Figure 5 This is a schematic diagram of the U-shaped feed network of the full-duplex antenna described in this invention;

[0025] Figure 6 This is a schematic diagram of the structure of the metal reflective cavity described in this invention;

[0026] Figure 7 The figure shows the simulation results of the relationship between the self-reflection coefficient and frequency in this invention.

[0027] Figure 8 The simulation results are shown in the figure. This is a graph illustrating the relationship between isolation and frequency in this invention.

[0028] Figure 9This is the far-field radiation pattern of the present invention when Phi = 0° at 3 GHz in vertical polarization mode;

[0029] Figure 10 This is the far-field radiation pattern of the present invention when Phi = 90° at 3 GHz, operating in vertical polarization mode;

[0030] Figure 11 This is the far-field radiation pattern of the present invention when Phi = 0° at 3 GHz, operating in horizontal polarization mode;

[0031] Figure 12 This is the far-field radiation pattern of the present invention when Phi = 90° at 3 GHz, operating in horizontal polarization mode.

[0032] Figure 13 The figure shows the simulation results of the relationship between gain and frequency when the present invention is operating in vertical polarization mode.

[0033] Figure 14 The figure shows the simulation results of the relationship between gain and frequency when the present invention is operating in horizontal polarization mode.

[0034] Explanation of symbols in the diagram: 1. First butterfly dipole; 2. Second butterfly dipole; 3. Third butterfly dipole; 4. Fourth butterfly dipole; 5. First dielectric substrate; 6. Second dielectric substrate; 7. Third dielectric substrate; 8. Ground plane; 9. Metal reflective cavity; 10. First T-slot; 11. Second T-slot; 12. Third T-slot; 13. Fourth T-slot; 14. First U-shaped feed network; 15. Second U-shaped feed network; 16. First group of signal transmission lines; 17. Second group of signal transmission lines; 18. Third group of signal transmission lines; 19. Fourth group of signal transmission lines; 20. First feed port; 21. Second feed port; 22. Parasitic metal strip; 9 01. First metal plate; 902. Second metal plate; 903. Third metal plate; 904. Fourth metal plate; 905. Fifth metal plate; 101. First trapezoidal dipole arm; 102. Second trapezoidal dipole arm; 2201. First metal narrow strip; 2202. Second metal narrow strip; 2203. Elliptical metal sheet; 1001. First rectangular slot; 1002. Second rectangular slot; 1401. First microstrip feed line; 1402. Second microstrip feed line; 1403. Third microstrip feed line; 1404. Fourth microstrip feed line; 1601. First transmission line; 1602. Second transmission line; 1603. Third transmission line; 1604. Fourth transmission line; Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 , 2 As shown in Figure 3, the present invention includes two pairs of butterfly dipole antennas, a first dielectric substrate 5, four sets of vertically placed signal transmission lines, a metal ground plate 8, a second dielectric substrate 6, two U-shaped feed networks, and a third dielectric substrate 7.

[0037] The two pairs of butterfly dipole antennas are respectively disposed on the upper and lower surfaces of the first dielectric substrate 5, and the two pairs of butterfly dipole antennas are placed perpendicular to each other to form a mutually perpendicular dual-polarization radiation mode.

[0038] The second dielectric substrate 6 is disposed below the first dielectric substrate 5, and the metal ground plate is located on the lower surface of the second dielectric substrate 6. The metal ground plate has four identical T-shaped slots, which are symmetrically distributed about the center of the metal ground plate, and the vertical parts of the four T-shaped slots are arranged concentrically. The spacing between a pair of opposite T-shaped slots is set to g2. The two pairs of butterfly dipole antennas are arranged corresponding to the four identical T-shaped slots through four sets of vertically placed signal transmission lines.

[0039] In actual use, the four sets of vertically placed first signal transmission lines 16, second signal transmission lines 17, third signal transmission lines 18, and fourth signal transmission lines 19 are used to differentially feed the first butterfly dipole 1, the second butterfly dipole 2, the third butterfly dipole 3, and the fourth butterfly dipole 4, respectively. The first set of signal transmission lines 16 is placed near the first T-shaped gap 10 to excite the first butterfly dipole 1; the second set of signal transmission lines 17 is placed near the second T-shaped gap 11 to excite the second butterfly dipole 2; the third set of signal transmission lines 18 is placed near the third T-shaped gap 12 to excite the third butterfly dipole 3; and the fourth set of signal transmission lines 19 is placed near the fourth T-shaped gap 13 to excite the fourth butterfly dipole 4. The signal transmission line is divided into multiple segments with varying widths from top to bottom. Specifically, the signal transmission line consists of a first transmission line 1601, a second transmission line 1602, a third transmission line 1603, and a fourth transmission line 1604, each with different widths, used to match the required impedance. The differential signal at the T-slot is transmitted to the dipole antenna via the transmission line, thereby providing balanced feeding to the two antenna arms of the dipole antenna.

[0040] The third dielectric plate 7 is disposed below the metal floor 8, and the two U-shaped power supply networks are respectively located on the upper surface of the second dielectric plate and the lower surface of the third dielectric plate; in the vertical angle from top to bottom, the two ends of one U-shaped power supply network are respectively perpendicularly intersecting the two long parts of one pair of T-shaped slots arranged opposite each other, and the two ends of the other U-shaped power supply network are respectively perpendicularly intersecting the two long parts of another pair of T-shaped slots arranged opposite each other.

[0041] The butterfly dipole antenna is composed of a pair of symmetrically placed trapezoidal metal patches, with the smaller ends facing each other, and the gap between the two metal patches is set to g1. Specifically, the first butterfly dipole antenna 1 and the second butterfly dipole antenna 2 are placed on the upper surface of the first dielectric substrate 5, and the third butterfly dipole antenna 3 and the fourth butterfly dipole antenna 4 are placed on the lower surface of the first dielectric substrate 5. The butterfly dipole antennas 1 and 2 are placed perpendicular to the butterfly dipole antennas 3 and 4. The butterfly dipole antenna is composed of a first trapezoidal dipole arm 101, a second trapezoidal dipole arm 102, and two parasitic metal strips 22. The first trapezoidal dipole arm 101... The distance between the first and second trapezoidal dipole arms 101 is g1. In actual use, to increase the antenna's operating bandwidth, a parasitic metal strip 22 is added near the feed end of the butterfly dipole to connect the two arms of the dipole antenna. The parasitic metal strip 22 is composed of a first narrow metal strip 2201, a second narrow metal strip 2202, and an elliptical metal sheet 2203. The two ends of the elliptical metal sheet 2203 are connected to the first narrow metal strip 2201 and the second narrow metal strip 2202, respectively. The butterfly dipole antenna can be integrally molded.

[0042] It also includes a metal reflector cavity, located below the third dielectric substrate, i.e., at the bottom of the antenna. This metal reflector cavity is a box-like structure without a cover, used to increase the far-field radiation gain of the antenna. In practical use, such as... Figure 6 As shown, the metal reflective cavity 9 is located below the third dielectric plate 7, and includes a horizontally placed first metal plate 901 and a second metal plate 902, a third metal plate 903, a fourth metal plate 904, and a fifth metal plate 905 disposed around the first metal plate 901. The second metal plate 902, the third metal plate 903, the fourth metal plate 904, and the fifth metal plate 905 are of the same size and have a height of 5mm. The distance between the bottom of the metal reflective cavity and the third dielectric plate is 5mm. In actual use, the height can be positioned and limited by support studs, or supported and fixed by foam board supports.

[0043] The U-shaped feed line includes a first microstrip feed line, a second microstrip feed line, a third microstrip feed line, and a fourth microstrip feed line. The second microstrip feed line is placed perpendicular to the first microstrip feed line. The third and fourth microstrip feed lines are respectively parallel and symmetrically arranged at both ends of the second microstrip feed line. The third and fourth microstrip feed lines have the same size. The first U-shaped feed network 14 is placed on the lower surface of the third dielectric substrate 7, and the second U-shaped feed network 15 is placed on the upper surface of the second dielectric substrate 6, thereby avoiding overlap of the feed networks.

[0044] In actual use, such as Figure 5 As shown, the first U-shaped power supply network 14 and the second U-shaped power supply network 15 have the same size and are placed perpendicularly to each other on the upper surface of the second dielectric plate 6 and the lower surface of the third dielectric plate 7. The U-shaped power supply network includes a first microstrip feed line 1401, a second microstrip feed line 1402, a third microstrip feed line 1403, and a fourth microstrip feed line 1404. The second microstrip line 1402 is placed perpendicularly to the first microstrip line 1401 and connected to the center of the first microstrip line 1401. The third microstrip line 1403 and the fourth microstrip line 1404 are respectively located at both ends of the second microstrip line 1402. The third microstrip line 1403 and the fourth microstrip line 1404 have the same size and are placed below the second rectangular slot 1002 that forms the T-shaped slot. The length of the third microstrip line 1403 and the fourth microstrip line 1404 extending out of the second rectangular slot 1002 is set to 6 mm.

[0045] The T-shaped coupling gap consists of a first gap and a second gap placed perpendicular to the first gap. Specifically, as shown... Figure 4 As shown, in actual use, the metal floor 8 is provided with a first T-shaped gap, a second T-shaped gap, a third T-shaped gap, and a fourth T-shaped gap. The metal floor 8 is located on the lower surface of the second dielectric plate 6. In order to achieve gap coupling power supply, four identical T-shaped gaps are etched in the center of the metal floor 8. The four T-shaped gaps are symmetrically distributed about the center of the metal floor. The spacing between a pair of T-shaped gaps that are opposite each other is set to g2. The T-shaped gap includes a first rectangular gap 1001 and a second gap 1002 perpendicular to the first gap 1001.

[0046] The first dielectric substrate 5, the second dielectric substrate 6, and the third dielectric substrate 7 can all be made of a substrate with a thickness of 1 mm and a dielectric constant of 4.4.

[0047] The distance between the bottom of the first dielectric substrate and the top of the second dielectric substrate is 36 mm.

[0048] To further verify the coverage, isolation, offset, and stability of this application, experimental simulations are conducted below:

[0049] Please see Figure 7 As shown, Figure 7 This paper presents simulation results illustrating the relationship between the self-reflection coefficients and frequencies at two ports of a full-duplex antenna based on slot-coupled differential feeding, according to an embodiment of the present invention. These simulation results were obtained after optimization using the commercial simulation software ANSYS HFSS_18.0. Figure 7 As shown, with a return loss greater than 10dB as the standard, the antenna operates in vertical polarization mode, covering a frequency range of 2.22GHz to 3.17GHz, and in horizontal polarization mode, covering a frequency range of 2.2GHz to 3.16GHz.

[0050] Please see Figure 8 As shown, Figure 8 This paper presents simulation results illustrating the relationship between isolation and frequency between two ports of a full-duplex antenna based on slot-coupled differential feeding, according to an embodiment of the present invention. The simulation results were obtained after optimization using the commercial simulation software ANSYS HFSS_18.0. Figure 8 As shown, within the operating frequency band (2.22GHz~3.17GHz), the isolation between the two feed ports is greater than 41dB, achieving a high level of isolation, which can be applied to simultaneous full-duplex communication systems.

[0051] Please see Figures 9 to 12 As shown, Figure 9 and Figure 10 The far-field radiation patterns of a full-duplex antenna based on slot-coupled differential feeding, provided by an embodiment of the present invention, are shown at 3 GHz when Phi = 0° and Phi = 90°, respectively, while operating in vertical polarization mode. Figure 11 and Figure 12 The far-field radiation patterns of a full-duplex antenna based on slot coupling differential feeding provided by the present invention are shown in horizontal polarization mode at 3 GHz when Phi = 0° and Phi = 90°. Regardless of whether it is horizontal or vertical polarization mode, the antenna's maximum radiation direction is the +z axis, without any deviation or lobe phenomenon. Moreover, within a 3-dB beamwidth, the cross polarization level is generally 32dB lower than the main polarization.

[0052] Please see Figures 13 to 14 As shown, Figure 13 and Figure 14 These are simulation results of the relationship between gain and frequency of a full-duplex antenna based on slot-coupled differential feeding, provided in an embodiment of the present invention, operating in vertical and horizontal polarization modes. Figure 13 and Figure 14As shown, the maximum gain obtained by vertical polarization is 11.9dB, and the maximum gain obtained by horizontal polarization is 10.8dB, both of which maintain relatively stable gains within the operating frequency band.

[0053] In summary, this invention discloses a full-duplex antenna based on slot-coupled differential feeding, comprising two pairs of butterfly dipole antennas, a first dielectric substrate, four sets of vertically placed feed lines, a metal ground plane with a T-slot, a second dielectric substrate, two U-shaped feed networks, a third dielectric substrate, and a metal reflector cavity. Based on the T-slot, U-shaped feed networks, and vertically placed signal transmission lines, differential feeding of the butterfly dipole antennas is achieved, ensuring that the maximum direction of the far-field radiation pattern follows the +z direction without deviation. To extend the antenna's operating bandwidth, a parasitic metal strip is designed. A metal reflector cavity is placed at the bottom of the antenna, further increasing the far-field radiation gain. Ultimately, this antenna achieves a wide operating bandwidth, high port isolation, and high gain, ensuring its promising application prospects in simultaneous, same-frequency full-duplex communication systems.

[0054] In the description of this invention, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0055] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0056] Note that the above description is merely a preferred embodiment and application of the technical principles of the present invention. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the specific embodiments described herein, and may include many other effective embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A full-duplex antenna based on slot-coupled differential feeding, characterized in that, It includes two pairs of butterfly dipole antennas, a first dielectric substrate, four sets of vertically placed signal transmission lines, a metal ground plane, a second dielectric substrate, two U-shaped feed networks, and a third dielectric substrate; The two pairs of butterfly dipole antennas are respectively disposed on the upper and lower surfaces of the first dielectric substrate, and the two pairs of butterfly dipole antennas are placed perpendicular to each other to form a mutually perpendicular dual-polarization radiation mode. The second dielectric substrate is disposed below the first dielectric substrate, and the metal ground plate is located on the lower surface of the second dielectric substrate. The metal ground plate has four identical T-shaped slots, which are symmetrically distributed about the center of the metal ground plate, and the vertical parts of the four T-shaped slots are arranged concentrically. The spacing between a pair of opposite T-shaped slots is set to g2. The two pairs of butterfly dipole antennas are arranged corresponding to the four identical T-shaped slots through four sets of vertically placed signal transmission lines. The third dielectric plate is disposed below the metal floor, and the two U-shaped power supply networks are respectively located on the upper surface of the second dielectric plate and the lower surface of the third dielectric plate. Vertically from top to bottom, one U-shaped power supply network has its two ends perpendicularly intersecting the two long portions of a pair of opposite T-shaped slots, and the other U-shaped power supply network has its two ends perpendicularly intersecting the two long portions of another pair of opposite T-shaped slots. It also includes a parasitic metal strip used to connect two opposing metal patches. The parasitic metal strip includes a first narrow metal strip, a second narrow metal strip, and two elliptical metal sheets. The first and second narrow metal strips are symmetrically arranged parallel to each other on two metal sheets, and their ends are connected by two elliptical metal sheets.

2. A full-duplex antenna based on slot-coupled differential feeding according to claim 1, characterized in that, The butterfly dipole antenna is composed of a pair of symmetrically placed trapezoidal metal patches, with the smaller ends facing each other, and the gap between the two metal patches is set as g1.

3. A full-duplex antenna based on slot-coupled differential feeding according to claim 1, characterized in that, It also includes a metal reflector cavity, which is located below the third dielectric substrate, i.e., at the bottom of the antenna. The metal reflector cavity is composed of a box structure without a cover, which is used to increase the far-field radiation gain of the antenna.

4. A full-duplex antenna based on slot-coupled differential feeding according to claim 1, characterized in that, The signal transmission line is divided into multiple segments from top to bottom, and the widths of the segments are different. Used to match the required impedance.

5. A full-duplex antenna based on slot-coupled differential feeding according to claim 1, characterized in that, The U-shaped power supply network includes a first microstrip feeder, a second microstrip feeder, a third microstrip feeder, and a fourth microstrip feeder. The midpoint of the second microstrip feeder is perpendicularly and fixedly connected to one end of the first microstrip feeder. The third and fourth microstrip feeders are respectively parallel and symmetrically arranged at both ends of the second microstrip feeder. The third and fourth microstrip feeders have the same structural size. The other end of the first microstrip feeder is used to connect to the power supply port.

6. A full-duplex antenna based on slot-coupled differential feeding according to claim 3, characterized in that, The metal reflective cavity is located below the third dielectric plate and includes a horizontally placed first metal plate and a second, third, fourth, and fifth metal plate vertically surrounding the first metal plate. The second, third, fourth, and fifth metal plates are of the same size and have a height of 5 mm. The distance between the bottom of the metal reflective cavity and the third dielectric plate is 5 mm.

7. A full-duplex antenna based on slot-coupled differential feeding according to claim 1, characterized in that, The T-shaped gap consists of a first gap and a second gap placed perpendicular to the first gap.

8. A full-duplex antenna based on slot-coupled differential feeding according to claim 5, characterized in that, The third and fourth microstrip lines of the U-shaped feed network are placed below the second slot that forms the T-shaped slot, and the length of the third and fourth microstrip lines extending out of the second slot is set to 6 mm.

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