Thin Ku / Ka waveband shared aperture phased array antenna with dual polarization and high isolation

Abstract

The invention belongs to the technical field of wireless communication and radar, and discloses a dual-polarization and high-isolation thin Ku / Ka wave band shared aperture phased-array antenna which is composed of a dual-polarization Ku element and four single-polarization Ka elements. According to the low-profile design, the profile height of the antenna is only 2.35 mm, and the antenna is crucial to the application field with limited space. The Ka wave band element works in the frequency band of 32-36 GHz, the Ku wave band element covers 14-18 GHz, and a wide frequency range is provided for various communication and radar applications. High isolation: the dual-polarization port of the Ku wave band shows the isolation higher than 30dB in a scanning range of 0-60 degrees, and the minimum interference between polarization is ensured. In addition, the channel isolation between the Ku wave band and the Ka wave band exceeds 35dB in the Ku wave band and exceeds 18dB in the Ka wave band, so that the signal integrity can be kept and the crosstalk can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communication and radar, and in particular relates to a thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation. Background Art

[0002] With the rapid development of wireless communication and radar technology, the demand for antennas that can operate efficiently across multiple frequency bands while maintaining a compact physical size continues to increase. The emergence of shared aperture (SA) antennas effectively solves this problem. Phased array antennas are particularly favored due to their beam steering capabilities and flexibility over a wide frequency band. Therefore, the design of dual-band shared aperture antennas (SAPA) has become a hot topic. However, it is a major challenge to realize dual-band SAPA antennas while maintaining a low profile, high isolation, and a wide scanning angle.

[0003] In recent years, various types of dual-band SAPA antennas have been reported. In the article Radiating Elements for Shared Aperture Tx / Rx PhasedArrays at K / Ka Band published by Ali Imran Sandhu et al. in IEEE in 2016, a transmit / receive self-duplex phased array antenna covering the K / Ka band was proposed. The array elements are optimized to achieve two-dimensional wide-angle scanning of ±50° in the two frequency bands, but the close arrangement of antenna elements may bring integration problems, especially the integration of transceiver modules and control signals in a limited space.

[0004] In 2019, Yan Ran Ding and Yu Jian Cheng reported a Ku / Ka dual-band shared aperture beam scanning antenna array based on the concept of structural reuse in the paper Ku / Ka Dual-Band Dual-Polarized Shared-Aperture Beam-Scanning Antenna Array With High Isolation. The antenna isolation is better than 28dB in the Ku band and better than 70dB in the Ka band, and the one-dimensional beam coverage range is ±40°. Although the antenna design enables wide-angle beam scanning, the scanning range may be limited when high isolation needs to be maintained.

[0005] A Low-Cost, Quad-Beam, Dual-Polarized, 2-D Leaky Wave Antenna With Wide-Angle Beam Scanning for Millimeter-Wave Applications, published by Yaling Chen, Long Zhang, et al. in 2023 in IEEE, proposed a dual-band SAPA antenna for 5G communications, which realizes dual polarization in two frequency bands and a two-dimensional beam scanning range of ±45°. However, radiation blind spots may occur when the beam approaches the wide side direction. Although the paper mentions taking measures to suppress the open bandgap (OSB) problem, completely eliminating OSB has additional requirements for the design.

[0006] Through the above analysis, the problems and defects of the prior art are as follows:

[0007] (1) The antenna elements of the prior art are closely arranged, which may cause integration difficulties, especially when integrating the transceiver module and the control signal in a limited space. In addition, closely arranged elements may cause mutual coupling problems, affecting the performance of the antenna.

[0008] (2) The existing dual-frequency shared aperture beam scanning antenna array can perform beam scanning within a range of ±40°, but the expansion of the scanning range may affect the antenna isolation. When pursuing a wider beam scanning range, the requirement for high isolation may limit the actual beam coverage.

[0009] (3) Existing dual-band SAPA antennas may have radiation blind spots when the beam approaches the broadside direction. This blind spot will reduce the radiation efficiency of the antenna in certain directions and affect the performance of the overall system. Summary of the invention

[0010] In view of the problems existing in the prior art, the present invention provides a thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation.

[0011] The present invention is implemented as follows: a thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation, comprising:

[0012] 1. Combination of dual-polarized Ku element and single-polarized Ka element: The antenna includes a dual-polarized Ku element and four single-polarized Ka elements. These Ka-band patch elements are arranged in a mirror image at the four corners of the dual-polarized Ku element.

[0013] 2. Multi-layer dielectric substrate structure: The overall configuration of the antenna includes seven layers of dielectric substrate, which use dielectric materials with different dielectric constants and loss tangents to meet the working requirements of different frequency bands.

[0014] 3. Defective ground structure (DGS) and H-shaped gap design: The structure of the Ka-band element includes a decoupling surface, a radiation patch, an H-shaped gap layer and a defective ground structure (DGS). The DGS is used to enhance the performance of the Ku-band and is formed by cutting an L-shaped patch and forming a cross-shaped gap in the center of the Ku-band element.

[0015] 4. Dual-polarization feeder: The Ku-band dual-polarization feeder is designed below the central cross-shaped slot, using cross-shaped patches to adjust impedance matching and enhance radiation performance.

[0016] Further, specifically including:

[0017] It consists of a dual-polarized Ku element and four single-polarized Ka elements;

[0018] The Ka-band patch elements are arranged in mirror images at the four corners of the dual-polarized Ku element;

[0019] The whole configuration includes seven layers of dielectric substrate, of which the first layer is F4BTMS350; relative dielectric constant εr = 3.50, loss tangent tanδ = 0.0024 at 40GHz;

[0020] The second to fourth layers are F4BME300; εr = 3.00, tanδ = 0.0025 at 20GHz;

[0021] The fifth to seventh layers are F4BME217; εr = 2.17, tanδ = 0.0014 at 20GHz;

[0022] Further, the Ka-band element thereof includes a total of five dielectric layers;

[0023] The first layer is the decoupling surface layer, the second layer is the radiation patch layer, the third layer is the H-shaped gap layer, the feeder is located on the fourth layer, and the fifth layer is the defective ground structure DGS;

[0024] The fifth layer has L-shaped patches cut out at four corners to form a defective ground structure.

[0025] Furthermore, the central cross-shaped slot of the Ku-band element is formed by the DGS of the Ka element, the Ku-band dual-polarization feed line is directly located below the cross-shaped slot, and there are two cross-shaped patches directly above the central cross-shaped slot for adjusting impedance matching and enhancing radiation performance.

[0026] Furthermore, a decoupling surface is provided on the upper surface of the first dielectric plate, which is composed of a square patch and four "L-shaped" parasitic patches, and the four "L-shaped" parasitic patches are evenly distributed in the four corners of the dielectric plate in a mouth shape.

[0027] Furthermore, a square-shaped radiation patch is provided in the middle of the upper surface of the second dielectric plate.

[0028] Furthermore, a transversely crossed “I”-shaped gap layer is provided on the upper surface of the third dielectric plate, and 16 metal vias are evenly arranged around it.

[0029] Furthermore, a transverse T-shaped microstrip feed line is provided on the upper surface of the fourth dielectric plate.

[0030] Furthermore, two cross-shaped radiation patches are provided in the center of the second dielectric plate and the fourth dielectric plate to adjust impedance matching and enhance radiation performance.

[0031] Furthermore, the sixth dielectric plate is a Ku-band dual-polarization feeder line, which is composed of two "T"-shaped feeders vertically crossed.

[0032] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0033] First, the present invention proposes an innovative low-profile Ku / Ka dual-band SAPA antenna that addresses these challenges with a series of breakthrough features:

[0034] (1) Low profile design: The antenna has a profile height of only 2.35 mm (0.28λh), which is critical for space-constrained applications such as aerospace and satellite communication systems.

[0035] (2) Wide operating bandwidth: Ka-band components operate in the 32-36 GHz frequency band, and Ku-band components cover 14-18 GHz, providing a wide frequency range for a variety of communications and radar applications.

[0036] (3) High isolation: The dual-polarization ports in the Ku band exhibit an isolation of more than 30 dB in the scanning range of 0-60°, ensuring minimal interference between polarizations. In addition, the channel isolation between the Ku band and the Ka band exceeds 35 dB in the Ku band and 18 dB in the Ka band, respectively, which is critical for maintaining signal integrity and reducing crosstalk.

[0037] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: The low profile design makes the antenna very suitable for aircraft, unmanned aerial vehicles (UAV), satellites and other aerospace vehicles, which helps to reduce weight, reduce drag, and improve the performance and efficiency of aircraft. The high isolation and wide-angle scanning capabilities make the antenna have important application value in military radar, electronic warfare and communication systems.

[0038] The technical solution of the present invention solves the technical problem that people have been eager to solve but have never succeeded in solving: the antenna has a very low profile height (2.35mm, i.e. 0.28λh), which is very valuable for space-constrained application scenarios, such as the aerospace field. The antenna can work in the Ku band (14-18GHz) and the Ka band (32-36GHz) at the same time, meeting the needs of multi-band communications and radar technology. The dual-polarization port of the Ku band achieves a port isolation of more than 30dB in a wide scanning range (0-60°), reducing interference between polarizations. The channel isolation between the Ku band and the Ka band is better than 35dB and 18dB, respectively, which helps to maintain signal integrity and reduce crosstalk. The Ka band element achieves ±45° E / H plane beam scanning at 34GHz. The Ku band element achieves ±55° E / H plane dual-polarization beam scanning at 16GHz. The use of mirror-arranged Ka band elements and displaced Ka band patch elements helps to suppress mutual coupling between the dual bands. Dielectric substrate materials with different dielectric constants and loss tangents were used to optimize the antenna performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural diagram of a thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation provided by an embodiment of the present invention.

[0040] Figure 2 It is a preliminary design diagram of the Ka-band unit structure provided in an embodiment of the present invention.

[0041] Figure 3 It is a simulation result diagram of the active standing wave ratio of the Ka-band unit structure with and without DGS provided in the embodiment of the present invention.

[0042] Figure 4 It is a simulation result diagram of the surface current of the Ka-band unit structure with and without DGS provided in the embodiment of the present invention.

[0043] Figure 5 The S parameter simulation results under periodic boundary conditions provided by the embodiment of the present invention show that in the range of 14 to 18 GHz, the S11 and S22 of the X-pol and Y-pol ports are both less than 10 dB, and the port isolation within the working bandwidth is greater than 37 dB. The 16 GHz unit patterns of the X-pol and Y-pol are almost the same, with a gain of 4.4 dBi and a cross-polarization lower than -50 dB.

[0044] Figure 6 a is the E / H plane scanning result of the Ku-band orthogonal port isolation provided by the embodiment of the present invention being above 30 dB within the working frequency band (14-18 GHz). Figure 6b shows that the channel isolation between the Ku- and Ka-band ports is greater than 18 dB in the 32-36 GHz range and greater than 35 dB in the 14-18 GHz range.

[0045] Figure 7 The embodiment of the present invention provides a far-field radiation pattern for a Ka-band array at 34 GHz and different scanning angles, wherein a peak gain of 22.7 dBi is achieved at 34 GHz, and a gain attenuation of less than 2 dB when scanning to 45°.

[0046] Figure 8 It is the active standing wave ratio (Active VSWR) of the Ka-band unit provided in an embodiment of the present invention. During the E-plane / H-plane beam scanning process, the active standing wave ratio is less than 3.

[0047] Fig. 9 This is the far-field radiation pattern of the SAPA at 16 GHz and different scanning angles provided by the embodiment of the present invention. The peak measured gain at 16 GHz is 21.93 dBi, and the gain is reduced within 1.55 dB when scanning to 45°, and the gain is reduced within 3.3 dB when scanning to 55°.

[0048] Fig.10 It is the active standing wave ratio (Active VSWR) of the Ku-band unit provided by the embodiment of the present invention. During the E-plane / H-plane beam scanning process, the active standing wave ratio is less than 3. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] like Figure 1 As shown, a thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation provided by an embodiment of the present invention includes: a dual-polarization Ku element and four single-polarization Ka elements. The Ka-band patch elements are arranged in a mirror image at the four corners of the dual-polarization Ku element. The entire configuration includes seven layers of dielectric substrate, of which the first layer is F4BTMS350 (relative dielectric constant ε r =3.50, loss tangent tanδ = 0.0024 at 40GHz), the second to fourth layers are F4BME300 (ε r =3.00, tanδ=0.0025 at 20GHz), the fifth to seventh layers are F4BME217 (ε r =2.17, tanδ=0.0014 at 20GHz). To ensure that no grating lobes appear in a wide scanning range.

[0051] like Figure 1 As shown in (a)(b)(c)(d), the main structure of the single-polarization Ka-band component is located in the first to fourth layers: the decoupling surface layer of the Ka-band component is on the first layer of F4BTMS350, and the radiation patch layer, H-slot layer and feed layer are on the second to fourth layers of F4BME300. The T-shaped feed line is enclosed in a square SIW cavity formed by metallized blind holes. Figure 1 As shown in (e), the fifth layer is the defective ground structure (DGS) of the Ka-band element, which can effectively reduce the coupling between Ka-band elements. Each Ka-band patch element is mirrored around the X / Y axis relative to the two adjacent Ka-band patch elements.

[0052] like Figure 1 As shown in (b)(d)(e)(f), the main structure of the dual-polarization Ku-band element is located on the second to sixth layers: the Ku-band feed layer is located on the fifth and sixth layers of F4BME217, and the radiation patch layer is located on the second and fourth layers of F4BME300. Figure 1 As shown in (f) and (g), two T-shaped feed lines occupy the upper and lower surfaces of the sixth layer, the main feed line is located on the upper surface of the sixth layer, and only a small part of the Y-polarization feed line bypasses the X-polarization feed line through the metallized through-hole on the lower surface of the sixth layer. Like the Ka-band feed line, the Ku-band dual-polarization feed line is also enclosed in the square SIW cavity.

[0053] 2. Design Process of Shared Aperture Antenna Unit

[0054] (I) Design of Ka-band unit and DGS

[0055] like Figure 2 The figure shows the preliminary design of the Ka-band unit structure, which includes 5 dielectric layers. The first layer is the decoupling surface layer, the second layer is the radiation patch layer, the third layer is the H-type slot layer, the feed line is located in the fourth layer, and the DGS is located in the fifth layer. The details of the DGS are shown in the figure, where the L-type patches are cut out at the four corners to form a defective ground structure.

[0056] The designed DGS can effectively reduce the coupling between units, thereby obtaining a better active standing wave ratio under periodic boundary conditions. In order to verify the effect of DGS, Figure 3 The simulation results of active standing wave ratio of Ka-band unit structure with and without DGS are given. Figure 4 The simulation results of the surface current of the Ka-band unit structure with and without DGS are given. It can be clearly seen from the comparison that the active standing wave ratio with DGS is significantly better than that without DGS. Figure 4The surface current distribution in shows that the current distribution at the edge of the cell with DGS is smaller, indicating that the coupling between cells is weaker, while the current distribution at the edge of the cell without DGS is stronger, indicating that the coupling between cells is stronger. The analysis shows that the designed DGS can meet the design requirements.

[0057] (II) Dual-polarization Ku-band unit design

[0058] In this unit, the Ka-band units are arranged in a mirror image, such as Figure 1 (e) It can be observed that, when combined, the DGS of the Ka unit perfectly forms the central cross gap of the Ku-band unit.

[0059] like Figure 1 As shown in (g), the Ku-band dual-polarization feeder is located directly below the cross slot. Figure 1 As shown in (b) and (d), there are two cross patches directly above the central cross gap, which are used to adjust impedance matching and enhance radiation performance.

[0060] Under periodic boundary conditions, the designed dual-polarization Ku-band unit was simulated. The simulation results are shown in Figure 5 shown. Figure 5 The S parameter simulation results in (a) show that in the range of 14 to 18 GHz, the S11 and S22 of the X-pol and Y-pol ports are both less than 10 dB, and the port isolation within the working bandwidth is greater than 37 dB. Figure 5 (B) The 16 GHz unit patterns of X-pol and Y-pol are almost identical, achieving a gain of 4.4 dBi and a cross-polarization of less than -50 dB.

[0061] also, Figure 5 (a) shows that the Ku-band orthogonal port isolation exceeds 30dBE / H surface scan within the operating frequency band (14-18GHz). Figure 5 (b) It can be seen that the channel isolation between the Ku and Ka band ports is greater than 18 dB in the range of 32 to 36 GHz and greater than 35 dB in the range of 14 to 18 GHz. As a result, the dual-polarization design of the Ku unit is achieved while ensuring wide bandwidth and high isolation.

[0062] (III) Simulation of finite antenna array

[0063] Two limited SAPA arrays, namely an 8×8 Ku-band array and an 8×8 Ka-band array, are used to verify their radiation and scanning performance. For the Ka-band array, the far-field radiation pattern at 34 GHz and different scanning angles is shown in Figure 2. Figure 7The peak gain achieved at 34 GHz is 22.7 dBi, and the gain attenuation when sweeping to 45° is less than 2 dB. In addition, the active voltage standing wave ratio (ActiveVSWR) of the Ka-band unit is shown in Figure 8 As shown, it is shown that the active voltage standing wave ratio is less than 3 during the E-plane / H-plane beam scanning process.

[0064] For the 8×8 Ku-band array, due to the symmetry of the X-pol and Y-pol structures, their performance is almost the same, such as Figure 7 The far-field radiation patterns of the proposed SAPA at 16 GHz and different scanning angles are shown in Fig. 9 At 16 GHz, the peak gain is 21.93 dBi. When scanning to 45° in the E / H plane, the maximum gain reduction during beam scanning is within 1.55 dB, and when scanning to 55°, it is within 3.3 dB. The active standing wave of the Ku-band unit is as follows: Fig.10 As shown, the beam scanning coverage of both the E-plane and the H-plane is kept below 3.

[0065] The present invention has the advantages of low profile, high working bandwidth, high isolation, wide-angle scanning, etc., and can be specifically applied to: military radar systems, aerospace communications, electronic reconnaissance, system remote sensing detection, emergency communication systems, multi-band radar systems, scientific research and education and other fields.

[0066] Two application embodiments of the present invention are:

[0067] Example 1: Dual-frequency shared aperture antenna for satellite communication system

[0068] The antenna is used for Ku / Ka band dual-frequency communication in satellite communication systems. In order to meet the needs of multi-band satellite communication, the antenna needs to have high isolation and low profile to reduce mutual interference and ensure the compactness of the antenna.

[0069] Dual-polarized Ku element: used to send and receive signals in the Ku band (12-18GHz). The dual-polarized feed line is located on the sixth layer of the seven-layer dielectric board, and dual polarization is achieved by vertically crossing two "T"-shaped feed lines. The dual-polarized signal in the Ku band is coupled to the radiation patch layer (second layer) through the H-shaped slot layer (third layer) in the antenna structure to achieve signal radiation. The cross-shaped radiation patch (second and fourth layers) is used to adjust the impedance matching to enhance the radiation performance.

[0070] Single-polarized Ka element: Located at the four corners of the Ku element, it is arranged in a mirror image and is used for signal transmission in the Ka band (26.5-40GHz). The single-polarized signal in the Ka band is radiated through the defective ground structure (DGS, the third and fifth layers). The DGS in the Ka band forms a cross-shaped gap in the center of the Ku band to enhance isolation and reduce mutual interference.

[0071] Decoupling surface: The first dielectric board has a decoupling surface, which consists of a square patch and four L-shaped parasitic patches, evenly distributed at the four corners of the dielectric board. This structure is designed to reduce mutual interference between Ku / Ka bands and improve isolation.

[0072] Overall structure: The antenna adopts a seven-layer dielectric substrate design, in which the first layer is used for decoupling, the second layer is used for radiation, the third layer is an H-shaped slot layer, the fourth layer is used for feeding, the fifth layer is DGS, the sixth layer is a Ku-band feeder, and the seventh layer is used for structural support.

[0073] The antenna achieves efficient signal transmission in both Ku and Ka bands and maintains excellent isolation between Ku and Ka bands. Its low profile design is suitable for the space constraints of satellite communication systems while maintaining wide-angle beam scanning capabilities.

[0074] Example 2: Dual-band shared aperture antenna for 5G communication base station

[0075] The antenna is designed for 5G communication base stations, covering the communication needs of Ku and Ka bands. As 5G communication has high requirements for the miniaturization and high efficiency of antennas, the antenna adopts a thin design to fit into the compact installation space and achieve high isolation of dual bands.

[0076] Dual-polarized Ku element: It is also used for dual-polarized transmission of Ku-band signals. The Ku-band signal is transmitted to the radiation layer (the second layer) through the dual-polarized feeder (the sixth layer) in the structure to achieve wide-angle beam scanning. In a high-density 5G communication environment, this design can effectively improve communication reliability and signal coverage.

[0077] Single-polarized Ka element: The arrangement of the Ka-band element is similar to that of Example 1, located at the four corners of the Ku element and arranged in a mirror image. The Ka-band signal is transmitted through the L-shaped DGS and H-shaped slot layers, and impedance matching and radiation enhancement are performed through the cross-shaped patches of the second and fourth layers.

[0078] Decoupling surface and DGS: The decoupling surface design on the first layer of dielectric board reduces the mutual interference between Ku / Ka bands. The fifth layer of DGS further improves the isolation through the L-shaped cutting structure and cross-shaped gap design, ensuring the clarity of Ka-band signals.

[0079] Actual effect: In 5G base station applications, the antenna demonstrates excellent signal coverage and high isolation, especially in high-density urban environments, effectively reducing interference and providing stable dual-band communication support. The thin design of the antenna makes it easy to install and saves physical space without affecting performance.

[0080] In order to verify the effect of DGS, Figure 3 The simulation results of active standing wave ratio of Ka-band unit structure with and without DGS are given. Figure 4 The simulation results of the surface current of the Ka-band unit structure with and without DGS are given. It can be clearly seen from the comparison that the active standing wave ratio with DGS is significantly better than that without DGS. Figure 4 The surface current distribution in shows that the current distribution at the edge of the cell with DGS is smaller, indicating that the coupling between cells is weaker, while the current distribution at the edge of the cell without DGS is stronger, indicating that the coupling between cells is stronger. The analysis shows that the designed DGS can meet the design requirements.

[0081] Under periodic boundary conditions, the designed dual-polarization Ku-band unit was simulated. The simulation results are shown in Figure 5 shown. Figure 5 The S parameter simulation results in (a) show that in the range of 14 to 18 GHz, the S11 and S22 of the X-pol and Y-pol ports are both less than 10 dB, and the port isolation within the working bandwidth is greater than 37 dB. Figure 5 (b) shows that the 16 GHz unit patterns of X-pol and Y-pol are almost identical, achieving a gain of 4.4 dBi and a cross-polarization of less than -50 dB.

[0082] also, Figure 5 (a) E / H scan showing that the Ku-band orthogonal port isolation exceeds 30 dB within the operating frequency band (14-18 GHz). Figure 5 (b) It can be seen that the channel isolation between the Ku and Ka band ports is greater than 18 dB in the range of 32 to 36 GHz and greater than 35 dB in the range of 14 to 18 GHz. As a result, the dual-polarization design of the Ku unit is achieved while ensuring wide bandwidth and high isolation.

[0083] (III) Simulation of finite antenna array

[0084] Two limited SAPA arrays, namely an 8×8 Ku-band array and an 8×8 Ka-band array, are used to verify their radiation and scanning performance. For the Ka-band array, the far-field radiation pattern at 34 GHz and different scanning angles is shown in Figure 2. Figure 7The peak gain achieved at 34 GHz is 22.7 dBi, and the gain attenuation when sweeping to 45° is less than 2 dB. In addition, the active voltage standing wave ratio (ActiveVSWR) of the Ka-band unit is shown in Figure 8 As shown, it is shown that the active voltage standing wave ratio is less than 3 during the E-plane / H-plane beam scanning process.

[0085] For the 8×8 Ku-band array, due to the symmetry of the X-pol and Y-pol structures, their performance is almost the same, such as Figure 7 The far-field radiation patterns of the proposed SAPA at 16 GHz and different scanning angles are shown in Fig. 9 At 16 GHz, the peak gain is 21.93 dBi. When scanning to 45° in the E / H plane, the maximum gain reduction during beam scanning is within 1.55 dB, and when scanning to 55°, it is within 3.3 dB. The active standing wave of the Ku-band unit is as follows: Fig.10 As shown, the beam scanning coverage of both the E-plane and the H-plane is kept below 3.

[0086] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation, characterized in that: The antenna comprises a dual-polarization Ku element and four single-polarization Ka elements. The Ka-band patch elements are arranged in a mirror image at the four corners of the dual-polarization Ku element. The antenna structure is composed of seven layers of dielectric substrates, including a decoupling surface of a first dielectric plate, a radiation patch of a second dielectric plate, an H-shaped slot layer of a third dielectric plate, a T-shaped microstrip feed line of a fourth dielectric plate, and a defective ground structure (DGS) of a fifth dielectric plate. The DGS is formed in the Ka-band element and forms a cross-shaped slot at the center of the Ku-band element. The Ku-band dual-polarization feed line is located below the cross-shaped slot. Impedance matching and radiation performance enhancement are achieved by means of cross-shaped patches arranged on the second and fourth dielectric plates.

2. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 1, characterized in that: Specifically include: It consists of a dual-polarized Ku element and four single-polarized Ka elements; The Ka-band patch elements are arranged in mirror images at the four corners of the dual-polarized Ku element; The whole configuration includes seven layers of dielectric substrate, of which the first layer is F4BTMS350; relative dielectric constant εr = 3.50, loss tangent tanδ = 0.0024 at 40GHz; The second to fourth layers are F4BME300; εr = 3.00, tanδ = 0.0025 at 20GHz; The fifth to seventh layers are F4BME217; εr = 2.17, tanδ = 0.0014 at 20GHz; The spacing between adjacent SAPA elements is designed to be 1.08λh×1.08λh; h is the free-space wavelength of the highest operating frequency band.

3. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 2, characterized in that: Its Ka-band element includes a total of five dielectric layers; The first layer is the decoupling surface layer, the second layer is the radiation patch layer, the third layer is the H-shaped gap layer, the feeder is located on the fourth layer, and the fifth layer is the defective ground structure DGS; The fifth layer has L-shaped patches cut out at four corners to form a defective ground structure.

4. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 2, characterized in that: The DGS of the Ka element forms the central cross-shaped slot of the Ku-band element. The Ku-band dual-polarization feed line is directly located below the cross-shaped slot. There are two cross-shaped patches directly above the central cross-shaped slot for adjusting impedance matching and enhancing radiation performance.

5. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 3, characterized in that: The upper surface of the first dielectric plate is provided with a decoupling surface, which is composed of a square patch and four "L-shaped" parasitic patches. The four "L-shaped" parasitic patches are evenly distributed at the four corners of the dielectric plate in a mouth shape.

6. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 3, characterized in that: A square-shaped radiation patch is arranged in the middle of the upper surface of the second dielectric plate.

7. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 3, characterized in that: The upper surface of the third dielectric plate is provided with a transverse "I"-shaped gap layer, and 16 metal vias are evenly arranged around it.

8. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 3, characterized in that: A transverse T-shaped microstrip feed line is arranged on the upper surface of the fourth dielectric plate.

9. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 3, characterized in that: There are two cross-shaped radiation patches in the center of the second dielectric plate and the fourth dielectric plate to adjust impedance matching and enhance radiation performance.

10. The thin Ku / Ka band shared aperture phased array antenna with dual polarization and high isolation as claimed in claim 3, characterized in that: The sixth dielectric plate is a Ku-band dual-polarization feeder line, which is composed of two "T"-shaped feeders that cross vertically.

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