High-Integration In-Band and Out-of-Band Low-RCS Transmissive Array Antenna

Abstract

This application relates to the technical fields of radar and antennas, and particularly relates to a high-integration in-band and out-of-band low-RCS transmissive array antenna. The transmissive array antenna includes a feed source and a transmissive array, and the transmissive array includes a plurality of radiation units and a dielectric substrate for supporting the radiation units; the radiation units include type-A radiation units and type-B radiation units; the dielectric substrate is divided into four quadrant regions with equal areas; a plurality of type-A radiation units are arranged periodically and equidistantly in the second quadrant region and the fourth quadrant region respectively, and a plurality of type-B radiation units are arranged periodically and equidistantly in the first quadrant region and the third quadrant region respectively. This application realizes the RCS reduction ability in-band and out-of-band on the basis of the traditional transmissive array antenna and improves the integration degree of the overall structure. In addition, the application breadth and action depth of the transmissive array antenna are also greatly improved.

Description

Technical Field

[0001] The present application relates to the technical fields of radar and antennas, and particularly relates to a high-integration in-band and out-of-band low-RCS transmissive array antenna. Background Art

[0002] With the intensification of the competition for electromagnetic rights, it is necessary to further improve the electromagnetic transceiver capabilities and electromagnetic stealth performance of equipment to adapt to different application scenarios. Through strict shape optimization and the application of absorbing materials, the radar cross section (RCS) of equipment has been significantly reduced. However, the reduction of the RCS of the antenna responsible for electromagnetic transceiver functions cannot be achieved by these technologies. In addition, with the rapid development of radar and communication systems, the demand for antennas with integrated functions such as high gain, circular polarization, and beam controllability is increasing, so as to increase the detection or communication distance and signal quality. Therefore, it is urgent to explore solutions for the stealth of these high-performance and multifunctional antennas.

[0003] The planar transmissive array antenna is a high-gain air-fed antenna that combines the advantages of planar microstrip array antennas and lens antennas. As a high-gain air-fed array antenna, it combines array antenna theory and optical principles at the same time, and can achieve high-gain radiation through a relatively simple structure, which has attracted the attention of many scholars and experts. Compared with planar reflectarray antennas, the planar transmissive array antenna does not have the problem of feed blockage, because the feed of the planar transmissive array antenna and the beam radiation direction are distributed on both sides of the array surface. Therefore, this makes the design of the transmissive array antenna simpler and more flexible. At the same time, because there is no feed blockage effect, in theory, it can achieve a higher aperture efficiency than reflectarray antennas, and the sidelobe level and cross-polarization level are lower, which can make the transmissive array antenna applicable to high-quality communication systems. Existing inventions have explored various methods to reduce the RCS of transmissive array antennas. For example, by using dielectric columns with different heights and band-pass frequency selective surfaces as phase shifters, a low-RCS transmissive array antenna has been realized. In addition, resistive asymmetric resonators have also been used to obtain absorption-transmission-absorption responses, and beam convergence has been achieved by rotating open resonators to control the transmission phase. However, these low-RCS transmissive array antennas lack the ability to reduce RCS within the transmission band and have a low degree of integration, and have problems such as weak adaptability and poor portability in actual use. Therefore, it is urgent to realize a transmissive array antenna with high-gain radiation, strong beam convergence ability, high integration, and low RCS characteristics in both the transmission band and out-of-band, so that it can adapt to different application scenarios and have the ability to face complex electromagnetic environments. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a high-integration in-band and out-of-band low-RCS transmissive array antenna, so as to solve the problems that traditional low-RCS transmissive array antennas lack beam convergence ability and have low integration level, and improve the application breadth and function depth of the antenna.

[0005] To achieve the above purpose, the present application provides a high-integration in-band and out-of-band low-RCS transmissive array antenna. The transmissive array antenna includes a feed source and a transmissive array. The transmissive array includes a plurality of radiation units and a dielectric substrate for supporting the radiation units. The radiation units include type-A radiation units and type-B radiation units. Taking the center of the dielectric substrate as the origin, the dielectric substrate is divided into four quadrant regions with equal areas by two mutually orthogonal axes. A plurality of type-A radiation units are arranged periodically and equidistantly in the second quadrant region and the fourth quadrant region respectively, and a plurality of type-B radiation units are arranged periodically and equidistantly in the first quadrant region and the third quadrant region respectively. Among them, the second quadrant region and the fourth quadrant region are centrosymmetric, and the first quadrant region and the third quadrant region are centrosymmetric.

[0006] Further, in the embodiments of the present application, the polarization mode of the feed source is a linear polarization form.

[0007] Further, in the embodiments of the present application, the dielectric substrate includes a first dielectric substrate, a second dielectric substrate and a third dielectric substrate which are stacked in sequence. There is a first air layer between the first dielectric substrate and the second dielectric substrate, and a second air layer between the second dielectric substrate and the third dielectric substrate.

[0008] Further, in the embodiments of the present application, any type-A radiation unit includes a metal layer A1 attached to the top surface of the first dielectric substrate, a metal layer A2 attached to the top surface of the second dielectric substrate, a metal layer A3 attached to the bottom surface of the second dielectric substrate, and a metal layer A4 attached to the bottom surface of the third dielectric substrate. Any type-B radiation unit includes a metal layer B1 attached to the top surface of the first dielectric substrate, a metal layer B2 attached to the top surface of the second dielectric substrate, a metal layer B3 attached to the bottom surface of the second dielectric substrate, and a metal layer B4 attached to the bottom surface of the third dielectric substrate. The metal layers A1 to A4 are arranged in sequence, and the metal layers B1 to B4 are arranged in sequence.

[0009] Further, in the embodiment of the present application, the metal layer A1 includes a first-level cross-shaped patch a11 and four rectangular combined patches C1. The four rectangular combined patches C1 are respectively located at the upper left, lower left, upper right, and lower right positions of the first-level cross-shaped patch a11, and the distances between the four rectangular combined patches C1 and the first-level cross-shaped patch a11 are the same. Any one of the rectangular combined patches C1 is composed of four right-angled patches a12 that coincide with the four right angles of the rectangle and a second-level cross-shaped patch a13 located at the center of the rectangle. Among them, the four right-angled patches a12 and the second-level cross-shaped patch a13 are not connected to each other. The metal layer B1 includes a first-level cross-shaped patch b11 and four rectangular combined patches C2. The four rectangular combined patches C2 are respectively located at the upper left, lower left, upper right, and lower right positions of the first-level cross-shaped patch b11, and the distances between the four rectangular combined patches C2 and the first-level cross-shaped patch are the same. Any one of the rectangular combined patches C2 is composed of four right-angled patches b12 that coincide with the four right angles of the rectangle and a second-level cross-shaped patch b13 located at the center of the rectangle. Among them, the four right-angled patches b12 and the second-level cross-shaped patch b13 are not connected to each other. Among them, there are dimensional differences between the first-level cross-shaped patch a11 and the first-level cross-shaped patch b11; there are dimensional differences between the right-angled patch a12 and the right-angled patch b12; there are dimensional differences between the second-level cross-shaped patch a13 and the second-level cross-shaped patch b13.

[0010] Further, in the embodiment of the present application, the metal layer A2 includes four V-shaped groove metal patches a21; the openings of the four V-shaped groove metal patches a21 face the same direction. The projections of the four second-level cross-shaped patches a13 of the metal layer A1 on the top surface of the second dielectric substrate are four cross-shaped Y3s, and the vertices of the four V-shaped groove metal patches a21 coincide with the centers of the four cross-shaped Y3s respectively. The metal layer A3 includes four V-shaped groove metal patches a31; the vertices of the four V-shaped groove metal patches a31 coincide with the projections of the vertices of the four V-shaped groove metal patches a21 respectively. Among them, the opening direction of the V-shaped groove metal patch a31 is 90° different from the opening direction of the V-shaped groove metal patch a21. The metal layer B2 has the same structure as the metal layer A2; the metal layer B3 has the same structure as the metal layer A3.

[0011] Further, in the embodiment of the present application, when the opening direction of the V-shaped groove metal patch a31 is 90° different from the opening direction of the V-shaped groove metal patch a21 in the positive direction, the transmissive array antenna operates in the first transmission state; when the opening direction of the V-shaped groove metal patch a31 is 90° different from the opening direction of the V-shaped groove metal patch a21 in the negative direction, the transmissive array antenna operates in the second transmission state.

[0012] Further, in the embodiments of the present application, the metal layer A4 includes four secondary cross-shaped patches a41, and the four secondary cross-shaped patches a41 respectively coincide with the mappings of the four secondary cross-shaped patches a13 on the bottom surface of the third dielectric substrate; the metal layer B4 includes four secondary cross-shaped patches b41, and the four secondary cross-shaped patches b41 respectively coincide with the mappings of the four secondary cross-shaped patches b13 on the bottom surface of the third dielectric substrate.

[0013] Further, in the embodiments of the present application, the transmission frequency band of the transmissive array antenna is 12~14 GHz.

[0014] Further, in the embodiments of the present application, the reflection phase difference between the type A radiation unit and the type B radiation unit is maintained within the range of 180°±37°.

[0015] The high-integration in-band and out-of-band low-RCS transmissive array antenna provided by the present application has at least the following beneficial effects:

[0016] (1) By constructing a multi-mode resonance structure and efficiently utilizing each resonance mode to achieve different functions, the convergence of in-band radiation beams, the effective reduction of in-band radar cross-section area, and the effective reduction of out-of-band radar cross-section area can be simultaneously realized, thereby improving the electromagnetic transceiver ability and electromagnetic stealth ability of the antenna;

[0017] (2) The antenna structure is simple, with high integration and low cost, which is conducive to large-scale application.

[0018] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the embodiments of the present application, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the embodiments of the present application, but do not constitute a limitation to the embodiments of the present application. In the drawings:

[0020] Figure 1 A front view of the transmissive array antenna is schematically shown;

[0021] Figure 2 A schematic three-dimensional structure diagram of the transmissive array antenna is schematically shown;

[0022] Figure 3 A schematic three-dimensional structure diagram of the type A radiation unit is schematically shown;

[0023] Figure 4 A schematic structure diagram of the metal layer A4 of the type A radiation unit on the third dielectric substrate is schematically shown;

[0024] Figure 5 A schematic three-dimensional structure diagram of the type B radiation unit is schematically shown;

[0025] Figure 6 Schematically shows a layout diagram of the first metal layer of the transmissive array antenna;

[0026] Figure 7 Schematically shows a layout diagram of the second metal layer of the transmissive array antenna;

[0027] Figure 8 Schematically shows a layout diagram of the third metal layer of the transmissive array antenna;

[0028] Figure 9 Schematically shows a layout diagram of the fourth metal layer of the transmissive array antenna;

[0029] Figure 10 Schematically shows a structural diagram of the second metal layer and the third metal layer in the first transmission state (Bit0);

[0030] Figure 11 Schematically shows a structural diagram of the second metal layer and the third metal layer in the second transmission state (Bit1);

[0031] Figure 12 Schematically shows a transmission phase curve diagram of the second metal layer and the third metal layer of the transmissive array antenna in the first transmission state (Bit0) and the second transmission state (Bit1);

[0032] Figure 13 Schematically shows an in-band transmission amplitude curve diagram of the type A radiation element (element A) and the type B radiation element (element B);

[0033] Figure 14 Schematically shows an in-band reflection phase curve diagram of the type A radiation element (element A) and the type B radiation element (element B);

[0034] Figure 15 Schematically shows an out-of-band low-frequency reflection phase curve diagram of the type A radiation element (element A) and the type B radiation element (element B);

[0035] Figure 16 Schematically shows an out-of-band high-frequency reflection phase curve diagram of the type A radiation element (element A) and the type B radiation element (element B);

[0036] Figure 17 Schematically shows an in-band gain curve diagram of the transmissive array antenna;

[0037] Figure 18 Schematically shows an x-polarized RCS reduction performance curve diagram of the transmissive array antenna in-band and out-of-band.

[0038] Description of reference numerals

[0039] 1 - Feed; 2 - Transmissive array; 3 - First dielectric substrate; 4 - Second dielectric substrate; 5 - Third dielectric substrate; 6 - First metal layer; 7 - Second metal layer; 8 - Third metal layer; 9 - Fourth metal layer. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.

[0041] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0042] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application. Embodiment

[0043] As Figure 1 and Figure 2 shown, this embodiment provides a high-integration in-band and out-of-band low-RCS transmissive array antenna. The transmissive array antenna includes a feed 1 and a transmissive array 2. Among them, the feed 1 can be a key component in a radio telescope, a satellite communication system or other wireless communication devices. Its main function is to receive electromagnetic wave signals from a distance and convert them into processable electrical signals, or vice versa, to convert electrical signals into electromagnetic waves and emit them in the transmission mode. Its structure is usually a simple horn antenna or a more complex multi-mode feed 1 device. The operating frequency band of the feed 1 needs to cover the operating frequency band of the transmissive array 2.

[0044] The transmissive array 2 is a planar or curved structure composed of multiple antenna elements (taking the planar structure as an example in this embodiment), and these elements are usually arranged according to a certain rule. Each antenna element can independently emit electromagnetic waves, and the direction and shape of the beam emitted by the entire array can be controlled by adjusting the phase and amplitude of each element. Therefore, the function of beam convergence can also be achieved. In this embodiment, the feed source 1 is arranged at a preset position from the front surface of the transmissive array 2 for providing electromagnetic waves to the front surface. Specifically, in this embodiment, the transmissive array 2 includes a plurality of radiation elements and a dielectric substrate for supporting the radiation elements; the radiation elements include type A radiation elements and type B radiation elements; taking the center of the dielectric substrate as the origin, the dielectric substrate is divided into four quadrant regions with equal areas by using two mutually orthogonal axes (such as the Cartesian coordinate system); a plurality of type A radiation elements (a total of M type A radiation elements, where M≥2) are periodically arranged at equal intervals in the second quadrant region and the fourth quadrant region, and a plurality of type B radiation elements (a total of N type B radiation elements, where N≥2) are periodically arranged at equal intervals in the first quadrant region and the third quadrant region, as Figure 2 and Figure 6 shown; among them, the second quadrant region and the fourth quadrant region are centrosymmetric, and the first quadrant region and the third quadrant region are centrosymmetric.

[0045] Specifically, the dielectric substrate includes a first dielectric substrate 3, a second dielectric substrate 4, and a third dielectric substrate 5 which are stacked in sequence. The three dielectric substrates have the same size and can completely overlap. However, the first, second, and third dielectric substrates 5 are not completely tightly attached. There is a first air layer between the first dielectric substrate 3 and the second dielectric substrate 4, and a second air layer between the second dielectric substrate 4 and the third dielectric substrate 5.

[0046] Any type A radiation element includes a metal layer A1 attached to the top surface of the first dielectric substrate 3, a metal layer A2 attached to the top surface of the second dielectric substrate 4, a metal layer A3 attached to the bottom surface of the second dielectric substrate 4, and a metal layer A4 attached to the bottom surface of the third dielectric substrate 5; any type B radiation element includes a metal layer B1 attached to the top surface of the first dielectric substrate 3, a metal layer B2 attached to the top surface of the second dielectric substrate 4, a metal layer B3 attached to the bottom surface of the second dielectric substrate 4, and a metal layer B4 attached to the bottom surface of the third dielectric substrate 5; the metal layers A1~A4 are arranged in sequence, and the metal layers B1~B4 are arranged in sequence. In this embodiment, since the metal layer A1 of all type A radiation elements and the metal layer B1 of all type B radiation elements are attached to the same surface of the same dielectric substrate, for the convenience of understanding, the metal layer structure composed of all metal layer A1 and all metal layer B1 is named the first metal layer 6, and specific reference can be made to Figure 1 and Figure 6As shown in; similarly, the metal layer structure composed of all metal layers A2 and all metal layers B2 is named the second metal layer 7, for details, please refer to Figure 1 and Figure 7 As shown in; similarly, the metal layer structure composed of all metal layers A3 and all metal layers B3 is named the third metal layer 8, for details, please refer to Figure 1 and Figure 8 As shown in; similarly, the metal layer structure composed of all metal layers A4 and all metal layers B4 is named the fourth metal layer 9, for details, please refer to Figure 1 and Figure 9 As shown in. Embodiment

[0047] In this embodiment, the structures of the type A radiation unit and the type B radiation unit in Embodiment 1 are further described in detail. As Figure 3 shown, the metal layer A1 includes a first-level cross-shaped patch a11 and four rectangular combined patches C1. The four rectangular combined patches C1 are respectively located at the upper left, lower left, upper right, and lower right positions of the first-level cross-shaped patch a11, and the distances between the four rectangular combined patches C1 and the first-level cross-shaped patch a11 are the same; any one of the rectangular combined patches C1 is composed of four right-angle patches a12 that coincide with the four right angles of the rectangle and a second-level cross-shaped patch a13 located at the center of the rectangle. Among them, the four right-angle patches a12 and the second-level cross-shaped patch a13 are not connected to each other; as Figure 5 shown, the metal layer B1 includes a first-level cross-shaped patch b11 and four rectangular combined patches C2. The four rectangular combined patches C2 are respectively located at the upper left, lower left, upper right, and lower right positions of the first-level cross-shaped patch b11, and the distances between the four rectangular combined patches C2 and the first-level cross-shaped patch are the same; any one of the rectangular combined patches C2 is composed of four right-angle patches b12 that coincide with the four right angles of the rectangle and a second-level cross-shaped patch b13 located at the center of the rectangle. Among them, the four right-angle patches b12 and the second-level cross-shaped patch b13 are not connected to each other; among them, there are dimensional differences between the first-level cross-shaped patch a11 and the first-level cross-shaped patch b11; there are dimensional differences between the right-angle patch a12 and the right-angle patch b12; there are dimensional differences between the second-level cross-shaped patch a13 and the second-level cross-shaped patch b13.

[0048] The metal layer A2 includes four V-groove metal patches a21; the openings of the four V-groove metal patches a21 face the same direction; the four secondary cross-shaped patches a13 of the metal layer A1 are mapped to four cross-shaped Y3s on the top surface of the second dielectric substrate 4, and the vertices of the four V-groove metal patches a21 coincide with the centers of the four cross-shaped Y3s respectively; the metal layer A3 includes four V-groove metal patches a31; the vertices of the four V-groove metal patches a31 coincide with the vertices of the four V-groove metal patches a21 respectively; wherein, the opening direction of the V-groove metal patch a31 is 90° different from the opening direction of the V-groove metal patch a21 (the opening directions of the four V-groove metal patches a31 can be the same or different, but the opening direction of any one V-groove metal patch a31 is +90° or -90° different from the opening direction of the V-groove metal patch a21). The metal layer B2 has the same structure as the metal layer A2; the metal layer B3 has the same structure as the metal layer A3.

[0049] As Figure 10 shown, when the opening direction of the V-groove metal patch a31 is +90° different from the opening direction of the V-groove metal patch a21, the transmissive array antenna operates in the first transmission state; as Figure 11 shown, when the opening direction of the V-groove metal patch a31 is -90° different from the opening direction of the V-groove metal patch a21, the transmissive array antenna operates in the second transmission state. The transmission amplitudes of the first transmission state and the second transmission state are approximately the same, and the transmission phase difference is 180°. Figure 12 Let \(\varphi_{1}\) and \(\varphi_{2}\) be the transmission phases of the transmissive array antenna in the first transmission state (Bit0) and the second transmission state (Bit1) respectively. The transmission phase difference between the transmission state Bit0 and the transmission state Bit1 within the band can be stably maintained at 180°, indicating that the second metal layer 7 and the third metal layer 8 can achieve the function of in-band transmission beam convergence when arranged in a specific manner according to the transmission state Bit0 and the transmission state Bit1. Further, as Figure 13 shown, the operating frequency band of the A-type radiation unit (unit A in the figure) is wider than that of the B-type radiation unit (unit B in the figure). The entire transmissive array antenna is composed of the A-type radiation unit and the B-type radiation unit. Therefore, the operating frequency band of the entire transmissive array antenna is 12 - 14 GHz, and the in-band transmission amplitude performs well, indicating that the in-band transmission performance of the high-integration in-band and out-of-band low radar cross-section transmissive array antenna is good.

[0050] Further, in the embodiment of the present application, the metal layer A4 includes four secondary cross-shaped patches a41 (as Figure 4As shown in the figure, four secondary cross-shaped patches a41 respectively coincide with the mappings of four secondary cross-shaped patches a13 on the bottom surface of the third dielectric substrate 5; the metal layer B4 includes four secondary cross-shaped patches b41, and the four secondary cross-shaped patches b41 respectively coincide with the mappings of four secondary cross-shaped patches b13 on the bottom surface of the third dielectric substrate 5; for details, please refer to Figure 9 As shown in Figure 14 , Figure 15 and Figure 16 shown, due to the different sizes of the secondary cross-shaped patch a13 and the secondary cross-shaped patch b13, the different sizes of the primary cross-shaped patch a11 and the primary cross-shaped patch b11, and the different sizes of the right-angle patch a12 and the right-angle patch b12, the A-type radiation unit and the B-type radiation unit can respectively keep the reflection phase differences within the range of 180°±37° in the band (12~14 GHz), the out-of-band low frequency (8~10.5 GHz), and the out-of-band high frequency (15~17.7 GHz). Embodiment

[0051] Exemplarily, based on Embodiments 1 and 2, in this embodiment, by combining M = 32 A-type radiation units and N = 32 B-type radiation units, the combination method is as shown in Figures 6 - 8 shown, that is, there are 4×4 A-type radiation units in the upper left and lower right, and 4×4 B-type radiation units in the upper right and lower left, and the feed source 1 is placed at the position directly behind the array surface for simulation verification.

[0052] It can be seen from Figure 17 that the high-integration in-band and out-of-band low radar cross-section transmissive array antenna constructed in the embodiment of the present invention can realize the beam convergence function within 12~14 GHz.

[0053] Furthermore, as shown in Figure 18 shown, based on the traditional phased array antenna beam control theory, in this embodiment, by changing the in-band and out-of-band reflection phases of each unit, the incident electromagnetic wave can be diffusely reflected to different directions, so that more than 5 dB of x-polarization RCS reduction can be achieved within 12.5~14 GHz in the band, and more than 10 dB of x-polarization RCS reduction can be achieved within 8~10.5 GHz and 15~17.7 GHz outside the band, verifying the electromagnetic stealth ability of the reconfigurable circularly polarized transmissive array antenna with high integration and low radar cross-section.

[0054] It should also be noted that the term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements not only includes those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0055] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A high-integration in-band and out-of-band low RCS transmissive array antenna, the transmissive array antenna comprising a feed source and a transmissive array, characterized in that, The transmissive array includes a plurality of radiation units and a dielectric substrate for supporting the radiation units; the radiation units include type-A radiation units and type-B radiation units; Taking the center of the dielectric substrate as the origin, the dielectric substrate is divided into four quadrant regions with equal areas by two mutually orthogonal axes; a plurality of type-A radiation units are arranged periodically and equidistantly in the second quadrant region and the fourth quadrant region respectively, and a plurality of type-B radiation units are arranged periodically and equidistantly in the first quadrant region and the third quadrant region respectively; wherein, the second quadrant region and the fourth quadrant region are centrosymmetric, and the first quadrant region and the third quadrant region are centrosymmetric; wherein The dielectric substrate includes a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate which are stacked in sequence; there is a first air layer between the first dielectric substrate and the second dielectric substrate, and there is a second air layer between the second dielectric substrate and the third dielectric substrate; wherein Any type-A radiation unit includes a metal layer A1 attached to the top surface of the first dielectric substrate, a metal layer A2 attached to the top surface of the second dielectric substrate, a metal layer A3 attached to the bottom surface of the second dielectric substrate, and a metal layer A4 attached to the bottom surface of the third dielectric substrate; any type-B radiation unit includes a metal layer B1 attached to the top surface of the first dielectric substrate, a metal layer B2 attached to the top surface of the second dielectric substrate, a metal layer B3 attached to the bottom surface of the second dielectric substrate, and a metal layer B4 attached to the bottom surface of the third dielectric substrate; the metal layers A1 to A4 are arranged in sequence, and the metal layers B1 to B4 are arranged in sequence; wherein The metal layer A1 includes a first-level cross-shaped patch a11 and four rectangular combined patches C1. The four rectangular combined patches C1 are respectively located in the upper left, lower left, upper right, and lower right positions of the first-level cross-shaped patch a11, and the distances from the four rectangular combined patches C1 to the first-level cross-shaped patch a11 are the same; any rectangular combined patch C1 is composed of four right-angle patches a12 that coincide with the four right angles of the rectangle and a second-level cross-shaped patch a13 located at the center of the rectangle. Among them, the four right-angle patches a12 and the second-level cross-shaped patch a13 are not connected to each other; The metal layer B1 includes a first-level cross-shaped patch b11 and four rectangular combined patches C2. The four rectangular combined patches C2 are respectively located in the upper left, lower left, upper right, and lower right positions of the first-level cross-shaped patch b11, and the distances from the four rectangular combined patches C2 to the first-level cross-shaped patch are the same; any rectangular combined patch C2 is composed of four right-angle patches b12 that coincide with the four right angles of the rectangle and a second-level cross-shaped patch b13 located at the center of the rectangle. Among them, the four right-angle patches b12 and the second-level cross-shaped patch b13 are not connected to each other; Wherein, there are dimensional differences between the first-level cross-shaped patch a11 and the first-level cross-shaped patch b11; there are dimensional differences between the right-angle patch a12 and the right-angle patch b12; there are dimensional differences between the second-level cross-shaped patch a13 and the second-level cross-shaped patch b13.

2. The highly integrated in-band and out-of-band low RCS transmissive array antenna according to claim 1, wherein The metal layer A2 includes four V-groove metal patches a21; the openings of the four V-groove metal patches a21 face the same direction; the projections of the four secondary cross-shaped patches a13 of the metal layer A1 on the top surface of the second dielectric substrate are four cross-shaped Y3, and the vertices of the four V-groove metal patches a21 coincide with the centers of the four cross-shaped Y3 respectively; The metal layer A3 includes four V-groove metal patches a31; the vertices of the four V-groove metal patches a31 coincide with the projections of the vertices of the four V-groove metal patches a21 respectively; Among them, the opening direction of the V-groove metal patch a31 is 90° different from the opening direction of the V-groove metal patch a21; The metal layer B2 has the same structure as the metal layer A2; the metal layer B3 has the same structure as the metal layer A3.

3. The highly integrated in-band and out-of-band low RCS transmissive array antenna according to claim 2, wherein When the opening direction of the V-groove metal patch a31 is +90° different from the opening direction of the V-groove metal patch a21, the transmissive array antenna operates in the first transmission state; when the opening direction of the V-groove metal patch a31 is -90° different from the opening direction of the V-groove metal patch a21, the transmissive array antenna operates in the second transmission state.

4. The highly integrated in-band and out-of-band low RCS transmissive array antenna according to claim 1, wherein The metal layer A4 includes four secondary cross-shaped patches a41, and the four secondary cross-shaped patches a41 coincide with the projections of the four secondary cross-shaped patches a13 on the bottom surface of the third dielectric substrate respectively; The metal layer B4 includes four secondary cross-shaped patches b41, and the four secondary cross-shaped patches b41 coincide with the projections of the four secondary cross-shaped patches b13 on the bottom surface of the third dielectric substrate respectively.

5. The highly integrated in-band and out-of-band low-RCS transmissive array antenna according to any one of claims 1 to 4, characterized in that The polarization mode of the feed source is a linear polarization form.

6. The highly integrated in-band and out-of-band low RCS transmissive array antenna according to any one of claims 1 to 4, characterized in that, The operating frequency band of the transmissive array antenna is 12 - 14 GHz.

7. The highly integrated in-band and out-of-band low RCS transmissive array antenna according to any one of claims 1 to 4, wherein The reflection phase difference between the A-type radiation unit and the B-type radiation unit remains within the range of 180° ± 37°.

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