A millimeter wave broadband dual circular polarization antenna and array

Abstract

The present invention discloses a millimeter-wave broadband dual circularly polarized antenna and array, including two layers of microwave dielectric substrates, bonding dielectrics, grounded metal plates and coaxial feeding probes. Two E-shaped patch antennas, four small square patches with oblique slits in the center and an L-shaped metal strip used to increase port isolation are printed on the upper surface of the upper dielectric substrate, and the four small square patches are excited by the E-shaped patches to achieve broadband radiation characteristics. The two coaxial feeding probes are respectively connected to the two output ends of the 3dB directional coupler with a phase difference of 90 degrees on the lower surface of the lower microwave dielectric substrate, and pass through the lower microwave dielectric substrate, bonding dielectric, grounded metal plate, and upper microwave dielectric substrate in turn to achieve electrical connection with the two E-shaped patch antennas, thereby achieving circularly polarized radiation. The present invention realizes a circularly polarized antenna with wide beam width, wide impedance bandwidth, wide axial ratio bandwidth, and dual polarization characteristics, which is suitable for the potential application needs of wireless communication and satellite communication in the millimeter wave frequency band.

Description

Technical Field

[0001] The present invention belongs to the field of wireless communication technology, and in particular relates to a broadband dual circularly polarized antenna and array applied to millimeter wave wireless communication (5G) and millimeter wave satellite communication. Background Art

[0002] Due to its high data transmission rate and low latency, millimeter wave technology has become one of the most promising candidate technologies for the fifth generation (5G) and even the sixth generation (6G) of wireless communications. Dual-polarized antennas can transmit or receive two orthogonal linearly polarized or circularly polarized electromagnetic waves at the same time and frequency, and there is almost no interference between orthogonal channels. This allows the dual-polarized system to double the capacity of the single-polarized system under the same time, frequency and space resources. In addition, polarization diversity is an effective way to overcome the multipath fading phenomenon of wireless transmission and provide good target recognition, classification and anti-interference performance. Therefore, as a kind of diversity technology, dual-polarized antennas have very important application value in the field of wireless communications. At the same time, with the expectation of 6G and future communications, satellite communications are an important part of space networking, and there is an increasing demand for satellite communication antennas with superior performance. Circularly polarized antennas have a wide range of applications in satellite antennas because they have better ability to overcome the Faraday rotation effect and resist rain attenuation when generating and receiving circularly polarized electromagnetic waves. Therefore, broadband dual circularly polarized antennas for millimeter wave applications are of great significance for the high-speed, high-throughput transmission of wireless communication systems, and are one of the key components of future 6G satellite communication systems.

[0003] There are many ways to design and implement dual circularly polarized antennas. However, as the operating frequency continues to increase, there are still many design difficulties. For example: (1) It is difficult to achieve the broadband characteristics of dual polarized antennas through a single-layer dielectric substrate. In previous studies, the bandwidth of microstrip patch antennas was usually broadened by loading parasitic units, improving matching networks, and increasing the number of dielectric layers. This inevitably complicates the design and processing, and also makes the antenna lose some of its advantages of miniaturization and conformability. (2) The design of conventional antennas needs to consider indicators such as impedance matching, antenna axial ratio, and radiation gain at the same time. As a dual-port antenna, dual polarized antennas need to consider the isolation characteristics between the two ports. In a single-layer microwave dielectric substrate, it is easy for the two ports of the dual polarization to have port crosstalk, so it is difficult to obtain good port isolation. (3) When dual circularly polarized antennas are used for satellite communications or complex communications, there are special requirements for their radiation beams. Usually, the radiation beams are required to have spatial symmetry or rotational symmetry to ensure that good polarization characteristics are maintained within the radiation area. This also puts forward more stringent requirements for the design of circularly polarized antennas. (4) The design of broadband dual circularly polarized antennas not only needs to consider the 90-degree phase difference of the radiator (slot, metal patch), but also requires that the feeding port also needs to have a 90-degree phase difference. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a circularly polarized antenna and array operating in the millimeter wave frequency band, having wide beam width, wide impedance bandwidth, wide axial ratio bandwidth, and dual polarization characteristics, which has the advantages of simple processing, easy conformality with a curved carrier platform, and suitability for mass production.

[0005] Technical solution: To achieve the above-mentioned invention object, the present invention adopts the following technical solution:

[0006] A millimeter-wave broadband dual circular polarization antenna comprises an upper microwave dielectric substrate, a lower microwave dielectric substrate, a metal ground plate and two coaxial feeding probes; the upper surface of the upper microwave dielectric substrate is printed with two E-shaped patch antennas of the same shape and four small square patches of the same size;

[0007] The four small square patches of equal size enclose a large square; two E-shaped patch antennas are arranged outside two adjacent sides of the large square, and the two have a 90-degree structural rotation, the long sides are parallel and coupled with the large square patch, and the three branches point in the direction away from the large square; the middle branches of the two E-shaped patch antennas are connected to the coaxial feeding probe, and the two side branches are respectively connected to the metal ground plate through short-circuit metal through holes; each small square patch is provided with gaps distributed along the diagonal of the square, the two gaps on the same diagonal are parallel, and the four gaps are rotationally symmetric along the center of the large square;

[0008] An L-shaped metal strip is printed on the upper surface of the upper microwave dielectric substrate, located on a pair of sides of the large square without E-type patch coupling, and symmetrically distributed about the diagonal of the large square;

[0009] The upper microwave dielectric substrate is provided with a long strip metal guide hole connected to the metal ground plate, and four long strip metal guide holes are combined to form a larger square frame, enclosing the E-shaped patch antenna, four small square patches and the L-shaped metal strip;

[0010] A 3dB directional coupler with a microstrip line structure is printed on the lower surface of the lower microwave dielectric substrate, and two output ports with a phase difference of 90 degrees are connected to two coaxial feeding probes.

[0011] Preferably, the middle branch of the E-shaped patch antenna is longer than the two side branches, the middle section of the middle branch is connected to the coaxial feeding probe, and the ends of the two side branches are connected to the short-circuit metal through holes.

[0012] Preferably, the impedance bandwidth of the antenna unit is adjusted by adjusting the length of the E-shaped patch antenna trunk; the resonant frequencies of the low-frequency resonance points and the high-frequency resonance points in the reflection coefficient are changed by adjusting the length and distance of the E-shaped patch antenna branches; the strength of the coupling between the E-shaped patch antenna and the four small square patches is adjusted by adjusting the distance between the E-shaped patch antenna and the sides and vertices of the large square, thereby adjusting the reflection coefficient of the intermediate frequency band between the two resonance points and the isolation between the two ports.

[0013] Preferably, the two microwave dielectric substrates are bonded together by a bonding medium and share a common intermediate metal ground plane.

[0014] Preferably, the metal ground plate is located between the upper microwave dielectric substrate and the bonding medium, and the coaxial feeding probe passes through the upper microwave dielectric substrate, the metal ground plate, the bonding medium and the lower microwave dielectric substrate in sequence to form an electrical connection with the output port of the 3dB directional coupler.

[0015] Preferably, the 3dB directional coupler comprises an input port, a through port, a coupled port and an isolated port; wherein the through port and the coupled port serve as feeding output ports, outputting two feeding signals with equal amplitudes and a phase difference of 90 degrees; after swapping the input port and the isolated port, the through port and the coupled port remain as output ports, thereby constituting polarized antennas with different rotation directions.

[0016] Preferably, the widths of the gaps between the four small square patches of equal size are equal, and the widths of the gaps between the two E-shaped patch antennas and the sides of the large square are equal and greater than the widths of the gaps between the small square patches.

[0017] Preferably, after removing the bottom 3dB directional coupler feeding network structure and the corresponding bonding medium and the lower microwave dielectric substrate, feeding excitation with the same amplitude and phase is applied to the two coaxial probes, and the radiator of the antenna can realize two mutually orthogonal linearly polarized far-field radiations.

[0018] A millimeter wave broadband dual circular polarization antenna array comprises the millimeter wave broadband dual circular polarization antenna.

[0019] Preferably, a 2×2 antenna array is formed based on sequentially rotating 90-degree phase feeding, and the amplitude of the feeding port of each dual circular polarization antenna unit is equal, and a 90-degree phase difference is generated in sequence.

[0020] Working principle: The antenna structure proposed in the present invention has broadband dual circularly polarized radiation characteristics, and its working principle is mainly divided into three parts: (1) The present invention excites the E-shaped patch antenna through coaxial probe feeding, and excites the high-order mode radiation mode of four small square patches through the E-shaped patch antenna, thereby achieving the expansion of the system bandwidth. (2) The present invention uses a 3dB directional coupler to achieve a wide-band 90-degree phase difference. Within the working frequency band, the phase difference fluctuation range is ±4°, so the dual circularly polarized antenna also has a wider axial ratio bandwidth. By swapping the isolation end and the input end of the 3dB directional coupler, a circularly polarized antenna with different rotation directions can be obtained. (3) The present invention blocks the crosstalk current between the two ports to a certain extent by reasonably placing an L-shaped metal strip between the two ports, thereby effectively improving the isolation between the two ports.

[0021] Beneficial effects: The antenna of the present invention can be composed of a PCB board and a metal conductor, and the antenna radiation part is only designed on a layer of microwave dielectric substrate, which is conducive to the conformal conformity of the antenna to the curved carrier platform. It has a simple structure, high precision, and is easy to process and mass produce. Experiments show that the present invention effectively broadens the antenna bandwidth and axial ratio bandwidth, and the 3dB axial ratio bandwidth can reach 30%, completely covering the impedance bandwidth and n260 (37GHz-40GHz) frequency band of the antenna, and is suitable for 5G and 6G millimeter wave wireless communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a side structural schematic diagram of the present invention.

[0023] Figure 2 The figure is a schematic diagram of the metal structure printed on the upper surface of the upper microwave dielectric substrate of the present invention.

[0024] Figure 3 The figure is a schematic diagram of the metal structure printed on the lower surface of the lower microwave dielectric substrate of the present invention.

[0025] FIG. 4( a ) is a simulation diagram of S parameters of the dual circularly polarized antenna according to Embodiment 1 of the present invention.

[0026] FIG4( b ) is a simulation diagram of the gain and axial ratio of the dual circularly polarized antenna of Example 1 of the present invention.

[0027] FIG5(a) is a diagram showing the test and simulation results of the directional patterns of the dual circularly polarized antenna of Example 1 at 32 GHz in the planes of Phi=0° and phi=90°.

[0028] FIG5( b ) is a diagram showing the test and simulation results of the directional patterns of the dual circularly polarized antenna of Example 1 at 35 GHz in the planes of Phi=0° and phi=90°.

[0029] FIG5(c) is a diagram showing the test and simulation results of the directional patterns of the dual circularly polarized antenna of Example 1 at 38 GHz in the planes of Phi=0° and phi=90°.

[0030] Figure 6 This is the simulation efficiency diagram of the designed dual circularly polarized antenna.

[0031] Figure 7 It is a schematic structural diagram of a four-unit sequential rotation feeding antenna array according to Embodiment 2 of the present invention.

[0032] Figure 8 It is a simulation diagram of gain and axial ratio of the four-unit antenna array of Example 2 of the present invention.

[0033] FIG9( a ) is a diagram showing the simulation results of the directional patterns of the dual circularly polarized antenna array of Example 2 at 32 GHz in the planes of Phi=0° and phi=90°.

[0034] FIG9( b ) is a diagram showing the simulation results of the directional patterns of the dual circularly polarized antenna array of Example 2 at 35 GHz in the planes of Phi=0° and phi=90°.

[0035] FIG9( c ) is a diagram showing the simulation results of the directional patterns of the dual circularly polarized antenna array of Example 2 at 38 GHz in the planes of Phi=0° and phi=90°. DETAILED DESCRIPTION

[0036] The solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0037] like Figures 1 to 3The present invention discloses a millimeter wave broadband dual circular polarization antenna, comprising an upper microwave dielectric substrate 1-1, a lower microwave dielectric substrate 2-2, a metal grounding plate 12 and two coaxial feeding probes 5-1 and 5-2; two E-shaped patch antennas 3-1 and 3-2 of the same shape and four small square patches 4-1, 4-2, 4-3 and 4-4 of the same size are printed on the upper surface of the upper microwave dielectric substrate 1-1. The four small square patches of the same size are arranged into a large square, and the two E-shaped patch antennas are arranged on two adjacent sides of the large square surrounded by the four small square patches, and the two have a 90° structural rotation, in order to ensure that the long sides of the two E-shaped patches are parallelly coupled with the square patch and the three branches of the E-shaped patch point away from the large square. The middle sections of the slightly longer branches of the two E-shaped patch antennas are connected to the coaxial feeding probes 5-1 and 5-2 passing through the dielectric substrate 1-1, and the slightly shorter branch ends on both sides of the two E-shaped patches are respectively connected to two groups of short-circuit metal through holes 6-1, 6-2 and 6-3, 6-4, so as to achieve short circuit with the metal grounding plate 12 located between the dielectric substrate 1-1 and the bonding medium 2-1. Four identical slots 8-1, 8-2, 8-3, and 8-4 distributed along the diagonal of the square are respectively opened on the four small square patches to introduce perturbations to achieve circularly polarized radiation; the slots 8-1 and 8-3 are parallel to each other and distributed along the -45° direction, and the slots 8-2 and 8-4 are parallel to each other and distributed along the +45° direction, and the four slots are rotationally symmetric along the center of the large square. An L-shaped metal strip 7 is printed on the upper surface of the upper microwave dielectric 1-1, located on a pair of sides without E-type patch coupling arranged into a large square by four small squares, and is symmetrically distributed about the diagonal of the large square to achieve polarization mutual coupling cancellation. Long strip metal guide holes 9-1, 9-2, 9-3, 9-4 are opened in the microwave dielectric substrate 1 and connected to the metal ground plate 12, and their height is equal to the height of the microwave dielectric substrate 1-1; the four long strip metal guide holes are combined to form a larger square frame, enclosing the E-shaped patch antenna, the four small square patches and the L-shaped coupling line. A 3dB directional coupler 10 with a microstrip line structure is printed on the lower surface of the lower microwave dielectric substrate 2-2, which includes four ports 11-1, 11-2, 11-3 and 11-4.

[0038] In some embodiments, the impedance bandwidth of the antenna unit is adjusted by adjusting the length of the trunk of the E-shaped patch antenna. When the trunk length of the E-shaped patch antenna is close to twice the side length of the small square, the optimal impedance relative bandwidth can be obtained. By adjusting the length and distance of the branches of the E-shaped patch antenna, the resonant frequencies of the low-frequency resonance points and the high-frequency resonance points in the reflection coefficient are changed. By adjusting the distance between the E-shaped patch antenna and the sides and vertices of the large square, and adjusting the strength of the coupling between the E-shaped patch antenna and the four small square patches, the mid-frequency band reflection coefficient between the two resonance points and the two-port isolation can be adjusted. When the ratio of the spacing between the middle branch of the E-shaped patch antenna and the branches on both sides is approximately 1:2, the position relationship of the E-shaped patch antenna is consistent with the given illustrated structure, which is the optimal design position.

[0039] In some embodiments, two layers of microwave dielectric substrates are bonded by bonding medium, a metal ground plate 12 is located between the microwave dielectric substrate 1-1 and the bonding medium 2-1, and a 3dB directional coupler 10 is located on the lower surface of the microwave dielectric substrate 2-2, that is, the microwave dielectric substrate 1 and the microwave dielectric substrate 2-2 share the intermediate metal ground plate 12. Coaxial feeding probes 5-1 and 5-2 pass through the microwave dielectric substrate 1-1, the metal ground plate 12, the bonding medium 2-1 and the microwave dielectric substrate 2-2 in sequence, and are electrically connected to ports 11-2 and 11-3 of the 3dB directional coupler 10, respectively.

[0040] like Figure 3 , 3dB directional coupler 10, port 11-1 is the input port, port 11-2 is the through port, 11-3 is the coupling port, and 11-4 is the isolation port. Among them, ports 11-2 and 11-3 are used as feeding output ports, and output two feeding signals with equal amplitude and 90 degrees phase difference. If 11-4 is adjusted to be the input port, 11-1 is the isolation port, and 11-2 and 11-3 are still the output ports, polarized antennas with different rotation directions (left-hand or right-hand) can be formed.

[0041] The widths of the gaps between the four small square patches 4-1, 4-2, 4-3, and 4-4 of equal size are equal, and the widths of the gaps formed between the right sides of the square patches 4-1 and 4-4 and the E-shaped patch antenna 3-1 and the gaps formed between the lower sides of the square patches 4-3 and 4-4 and the E-shaped patch antenna 3-2 are equal, which are greater than the widths of the gaps between the small square patches.

[0042] In some embodiments, after removing the bottom 3dB directional coupler 10 feeding network structure and the corresponding bonding layer 2-1 and dielectric layer 2-2, the broadband dual circularly polarized antenna is subjected to two coaxial probes to apply feeding excitation with the same amplitude and phase. At this time, the radiator (slot, metal patch) of the antenna can realize two mutually orthogonal linearly polarized far-field radiations.

[0043] In some embodiments, the broadband dual circular polarization antenna can form a 2×2 antenna array based on sequentially rotating 90-degree phase feeding, that is, the feeding ports of the four antenna units 13-1, 13-2, 13-3, and 13-4 have equal amplitudes and sequentially generate 90-degree phase differences.

[0044] The effect of the present invention is verified by combining specific simulation experiments below.

[0045] Example 1: Figures 1 to 3 As shown, a millimeter-wave broadband dual circularly polarized antenna designed in an embodiment of the present invention specifically includes an upper microwave dielectric substrate 1, a bonding medium 2-1, and a lower microwave dielectric substrate 2-2. There are two E-shaped patch antennas 3-1 and 3-2 and four small square patches 4-1, 4-2, 4-3, and 4-4 of equal size in the upper microwave dielectric substrate 1-1. The two E-shaped patch antennas are connected to coaxial feeding probes 5-1 and 5-2, and short-circuited metal vias 6-1, 6-2, 6-3, and 6-4 connect the E-shaped patch antennas to the metal ground plane 12. Four identical slits 8-1, 8-2, 8-3, and 8-4 are opened on the four small square patches in a centrally symmetrical manner to introduce perturbations to achieve circularly polarized radiation. There is an L-shaped metal strip 7 in the upper microwave dielectric substrate 1-1, which is symmetrical about the diagonal of the overall antenna unit. Long metal guide holes 9-1, 9-2, 9-3, and 9-4 are located in the microwave dielectric substrate 1-1 and connected to the metal ground plane 12. Their height is equal to the height of the microwave dielectric substrate 1. A 3dB directional coupler 10 with a microstrip line structure is printed on the lower surface of the lower microwave dielectric substrate 2-2, which includes four ports 11-1, 11-2, 11-3, and 11-4. In this embodiment, the upper microwave dielectric substrate 1-1 is Rogers 4003C with a thickness of 0.813mm, the bonding medium 2-1 is Rogers 4450F with a thickness of 0.102mm, and the lower microwave dielectric substrate 2-2 is Rogers 5880 with a thickness of 0.254mm. The metal ground plane 12 is copper with a thickness of 0.035mm. The gap width between the four small square patches is 0.15mm. The designed antenna unit size is 7mm×7mm×1.274mm.

[0046] As shown in Figure 4(a), the impedance bandwidth of the designed antenna can cover 31.78 GHz to 41.26 GHz, and the port reflection coefficient is less than -10 dB.

[0047] As shown in Figure 4(b), the maximum gain of the designed antenna is 6.8dBic, the 3dB gain fluctuation bandwidth can cover 31.78GHz-41.26GHz, and the 3dB axial ratio bandwidth can cover 31.78GHz to 41.26GHz.

[0048] Figure 5(a)-Figure 5(c) The simulation results of the radiation patterns of the designed antenna in the E-plane and H-plane (phi=0°, phi=90°) at three typical frequency points of 32GHz, 35GHz and 38GHz are given. The designed antenna has a wide beamwidth in the two main planes, and the main polarization cross-polarization ratio can reach 22dB, and it remains stable within a wide bandwidth.

[0049] Figure 6 The simulation efficiency of the designed antenna is given. In the frequency band of 31.78GHz-41.26GHz, the efficiency of the antenna is greater than 70%, and the maximum efficiency can reach 95%.

[0050] The simulation results show that the dual circularly polarized antenna designed in Example 1 has the characteristics of wide beam width, wide impedance bandwidth, wide axial ratio bandwidth, good cross-polarization suppression and high gain, and is suitable for millimeter-wave wireless communications and satellite communication systems represented by 5G and 6G.

[0051] Example 2: Figure 7 As shown, the dual circular polarization antenna designed by Example 1 forms a 2×2 antenna array based on sequentially rotating 90° phase feeding. According to the rotation angle, the feeding amplitudes of the four antenna units are equal, and the phases are 0°, 90°, 180° and 270° respectively.

[0052] Figure 8 The achievable gain and axial ratio of the antenna within the frequency band are given. The maximum gain of the four-element sequential rotation antenna array is 12.66dBic, and the 3dB gain fluctuation bandwidth and axial ratio can cover 31.78GHz-41.26GHz.

[0053] Figure 9(a)-Figure 9(c) The simulation results of the radiation patterns of the designed antenna in the E-plane and H-plane (phi=0°, phi=90°) at three typical frequency points of 32GHz, 35GHz and 38GHz are given. The half-power lobe width of the designed antenna in the two main planes is 30°, the main polarization cross-polarization ratio can reach 55dB, and it remains stable within a wide bandwidth.

[0054] The simulation results show that the four-unit sequentially rotated circularly polarized antenna array designed in Example 2 has the characteristics of wide beam width, low sidelobe level, good cross-polarization suppression and high gain, and is suitable for the transceiver antenna array of millimeter wave wireless communication and satellite communication systems.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A millimeter wave broadband dual circular polarization antenna, characterized in that: It includes an upper microwave dielectric substrate, a lower microwave dielectric substrate, a metal grounding plate and two coaxial feeding probes; The upper surface of the upper microwave dielectric substrate is printed with two E-shaped patch antennas of the same shape and four small square patches of the same size; The four small square patches of equal size enclose a large square; two E-shaped patch antennas are arranged outside two adjacent sides of the large square, and the two have a 90-degree structural rotation, the long sides are parallel and coupled with the large square patch, and the three branches point in the direction away from the large square; the middle branches of the two E-shaped patch antennas are connected to the coaxial feeding probe, and the two side branches are respectively connected to the metal ground plate through short-circuit metal through holes; each small square patch is provided with gaps distributed along the diagonal of the square, the two gaps on the same diagonal are parallel, and the four gaps are rotationally symmetric along the center of the large square; An L-shaped metal strip is printed on the upper surface of the upper microwave dielectric substrate, located on a pair of sides of the large square without E-type patch coupling, and symmetrically distributed about the diagonal of the large square; The upper microwave dielectric substrate is provided with a long strip metal guide hole connected to the metal ground plate, and four long strip metal guide holes are combined to form a larger square frame, enclosing the E-shaped patch antenna, four small square patches and the L-shaped metal strip; A 3dB directional coupler with a microstrip line structure is printed on the lower surface of the lower microwave dielectric substrate, and two output ports with a phase difference of 90 degrees are connected to two coaxial feeding probes; The two microwave dielectric substrates are bonded by a bonding medium and share a middle metal grounding plate, which is located between the upper microwave dielectric substrate and the bonding medium.

2. The millimeter wave broadband dual circular polarization antenna according to claim 1, characterized in that: The middle branch of the E-shaped patch antenna is longer than the branches on both sides, the middle section of the middle branch is connected to the coaxial feeding probe, and the ends of the branches on both sides are connected to the short-circuit metal through holes.

3. The millimeter wave broadband dual circular polarization antenna according to claim 1, characterized in that: By adjusting the length of the trunk of the E-shaped patch antenna, the impedance bandwidth of the antenna unit can be adjusted; by adjusting the length and distance of the branches of the E-shaped patch antenna, the resonant frequencies of the low-frequency resonance points and the high-frequency resonance points in the reflection coefficient can be changed; by adjusting the distance between the E-shaped patch antenna and the side and vertex of the large square, the strength of the coupling between the E-shaped patch antenna and the four small square patches can be adjusted, thereby adjusting the reflection coefficient of the intermediate frequency band between the two resonance points and the isolation between the two ports.

4. The millimeter wave broadband dual circular polarization antenna according to claim 1, characterized in that: The coaxial feeding probe passes through the upper microwave dielectric substrate, the metal grounding plate, the bonding medium and the lower microwave dielectric substrate in sequence, and forms an electrical connection with the output port of the 3dB directional coupler.

5. The millimeter wave broadband dual circular polarization antenna according to claim 1, characterized in that: The 3dB directional coupler comprises an input port, a through port, a coupled port and an isolated port; wherein the through port and the coupled port serve as feeding output ports, outputting two feeding signals with equal amplitudes and a phase difference of 90 degrees; after swapping the input port and the isolated port, the through port and the coupled port remain as output ports, thus forming polarized antennas with different rotation directions.

6. The millimeter wave broadband dual circular polarization antenna according to claim 1, characterized in that: The widths of the gaps between the four small square patches of equal size are equal, and the widths of the gaps between the two E-shaped patch antennas and the sides of the large square are equal and greater than the widths of the gaps between the small square patches.

7. The millimeter wave broadband dual circular polarization antenna according to claim 1, characterized in that: After removing the bottom 3dB directional coupler feeding network structure and the corresponding bonding medium and the lower microwave dielectric substrate, feeding excitation with the same amplitude and phase is applied to the two coaxial probes, and the radiator of the antenna can realize two mutually orthogonal linear polarization far-field radiations.

8. A millimeter wave broadband dual circular polarization antenna array, characterized in that: It comprises a millimeter wave broadband dual circularly polarized antenna according to any one of claims 1 to 7.

9. The millimeter wave broadband dual circular polarization antenna array according to claim 8, characterized in that: A 2×2 antenna array is formed based on sequentially rotating 90-degree phase feeding, and the amplitude of the feeding port of each dual circular polarization antenna unit is equal, which generates a 90-degree phase difference in turn.

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