Transmission, reflection and scattering integrated three-frequency-band common-aperture array antenna

Abstract

The invention discloses a transmission, reflection and scattering integrated three-frequency-band common-aperture array antenna. The array antenna comprises a transmission unit, a reflection unit and a scattering unit. The transmission unit adopts a receiving-transmitting structure, the receiving structure is composed of a single-layer plane Vivaldi structure and a multi-stage fan-shaped microstrip line, the transmitting structure is composed of a single-layer plane eight-wood structure and a differential microstrip line, and 2-bit phase regulation and control are realized by simultaneously regulating and controlling the direction of the multi-stage fan-shaped microstrip line and the line length of the differential microstrip line. The reflection unit adopts a quasi-I-shaped metal step, and 1-bit phase regulation is realized by rotating the quasi-I-shaped metal step by 90 degrees. Scattering units are obtained by double-split square rings according to periodicity, and 1-bit phase regulation and control are achieved through mirroring operation. The reflecting unit and the scattering unit are consistent in size, are integrated in the same area, and are arranged on the front surface of the common metal ground on the two sides of the receiving structure of the transmission unit, so that the integration of transmission, reflection and scattering functions of three frequency bands is realized under a common port surface.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication, and more particularly, to a triple-band coplanar array antenna with integrated transmission, reflection, and scattering functions. Background Art

[0002] With the development of wireless communication technology, the requirements for antennas in communication systems are getting higher and higher. Traditional single-band and single-function antennas can no longer meet the needs of multi-band, high-performance, low-cost, and miniaturization, especially in communication systems that need to support multiple bands simultaneously and have diverse communication environments. To improve the frequency utilization rate, multi-band antennas that can process signals of multiple bands through the same array antenna have been proposed to optimize the spectrum utilization rate and effectively increase the information capacity of the communication system. On the other hand, multi-functional antennas integrate multiple radiation functions into the same array antenna, reducing the physical space occupancy rate of the communication system and expanding the application scenarios of the array antenna.

[0003] Currently, coplanar array antennas provide an effective solution for simultaneously achieving multi-function and multi-band capabilities. By stacking or integrating elements operating at different frequencies on the surface of the same dielectric layer, multi-functional radiation characteristics within multiple bands can be achieved. Among them, the array antenna using the stacking method can simultaneously achieve beam control in the front and rear half-spaces, that is, it can realize the functions of transmission, reflection, and scattering at multiple frequencies. However, with the increase in frequency bands or functions, the coplanar array antenna using the stacking method will result in a large number of dielectric layers, and a certain air gap needs to be left between each layer, which greatly increases the cost and complexity of the array antenna and reduces its stability. To improve the integration level, scholars often choose to integrate two elements with different frequency bands in a staggered manner to realize the design of a multi-functional array antenna within the dual band. However, this method limits the functions of the array antenna and can only achieve beam domain control within the front half-space.

[0004] With the increasing complexity of the current communication environment, modern communication systems have an increasingly strong demand for array antennas with multi-band, multi-functional, low-cost, and high-stability characteristics. Based on this, the present invention proposes a triple-band coplanar array antenna with integrated transmission, reflection, and scattering functions, which uses a coplanar structure to integrate the functions of transmission, reflection, and scattering, and has the advantages of multi-function, high integration level, high stability, simple and reliable system, and low cost, and is expected to be widely used in modern communication systems. Summary of the Invention

[0005] The present invention provides a triple-band coplanar array antenna with integrated transmission, reflection, and scattering functions, which has the advantages of multi-function, high integration level, high stability, simple and reliable system, and low cost.

[0006] To achieve the above object, the present invention provides the following technical solution: A triple-band common-aperture array antenna with integrated transmission, reflection, and scattering functions. The array antenna includes: a transmission unit (1), where the transmission unit (1) adopts a receive-transmit structure placed along the z-axis and operates in the 5.8 GHz band; the receive structure (11) of the receive-transmit structure consists of a single-layer planar Vivaldi structure (111) and a multi-stage fan-shaped microstrip line (112); the transmit structure (12) of the receive-transmit structure consists of a single-layer planar octagonal structure (121) and a differential microstrip line (122); the receive structure (11) and the transmit structure (12) are respectively placed on the front and back of a common metal ground (13) arranged along the xoy plane, and are connected to each other through a metal connecting rod (14); a reflection unit (2), where the reflection unit (2) adopts a quasi-I-shaped metal ladder (21) and operates in the 12.5 GHz band; a scattering unit (3), where the scattering unit (3) is obtained by periodically arranging double-slit square rings, and the resonance pattern is set at the four corners of the unit and operates in the 18.0 GHz band; wherein, the reflection unit (2) and the scattering unit (3) have the same size and are integrated on the same square area; the integrated reflection unit (2) and scattering unit (3) are arranged on the front of the common metal ground (13) on both sides of the receive structure (11) of the transmission unit (1), and a transmission mode in the 5.8 GHz band, a reflection mode in the 12.5 GHz band, and a scattering mode in the 18.0 GHz band are realized under the common aperture.

[0007] Further, the single-layer planar Vivaldi structure (111) of the transmission unit (1) is a single-sided etching structure, and curve slits (1111) are provided at both ends thereof to cut the current to achieve miniaturization; first rectangular slits (1112) are provided at both ends of the back of the multi-stage fan-shaped microstrip line (112) of the transmission unit (1) to suppress the stray current to reduce the sidelobe level; the transmission unit (1) adopts a triangular patch array (1113) with an increasing number, staggered positions, and double-sided etching along the +z direction as a director to improve the impedance matching within the operating band to broaden the operating bandwidth; the single-layer planar octagonal structure (121) of the transmission unit (1) is a single-sided etching structure, and second rectangular slits (1211) are provided at both ends of the bottom of the back of the differential microstrip line (122) to suppress the stray current to reduce the sidelobe level; the single-layer planar octagonal structure (121) adopts a rectangular patch array (1212) with staggered positions and double-sided etching along the +z direction as a director to concentrate the electromagnetic waves along the +z direction within the operating band to improve the gain.

[0008] Furthermore, the transmission unit (1) performs a mirror operation on the multi-level sector-shaped microstrip line (112) along the z-axis to reverse the surface current distribution of the single-layer planar Vivaldi structure (111), achieving a 180° phase change; the transmission unit (1) achieves a 90° phase change by changing the line length of the differential microstrip line (122); by simultaneously adjusting the direction of the multi-level sector-shaped microstrip line (112) and the line length of the differential microstrip line (122), 2-bit phase control in the y polarization is achieved.

[0009] Furthermore, the reflection coefficients of the reflection unit (2) in the x and y polarizations differ in phase by 180°; rotating the quasi-I-shaped metal ladder (21) 90° along the z-axis achieves 1-bit phase control in the x and y polarizations.

[0010] Furthermore, the reflection coefficients of the scattering unit (3) in the ±45° linear polarizations differ in phase by 180°; when an x- or y-polarized wave is incident on the scattering unit (3), the polarization direction of the outgoing polarized wave will rotate by 90°; mirroring the scattering unit (3) along the y-axis achieves 1-bit phase control in the x and y polarizations.

[0011] Furthermore, the transmission mode operates in a beam focusing state, and the ideal transmission phase distribution of the transmission unit (1) is set as: where, is the ideal transmission phase of the transmission unit (1) in the m-th row and n-th column, k t is the phase constant in vacuum, r fmn is the distance from the feed to the transmission unit (1), is the main beam direction in the transmission mode, is the direction vector from the center of the array plane to the transmission unit (1), is a constant; the ideal transmission phase is normalized according to a 360° phase cycle to obtain a normalized phase in the range of [0°, 360°), and the normalized phase is normalized with the 2-bit phase to obtain the actual transmission phase The reflection mode operates in a beam focusing state, and the ideal reflection phase distribution of the reflection unit (2) is set as: where, is the ideal reflection phase of the reflection unit (2) in the p-th row and q-th column, k r is the phase constant in vacuum, r fpq is the distance from the feed to the reflection unit (2), is the main beam direction in the reflection mode, is the direction vector from the center of the array plane to the reflection unit (2), is a constant; the ideal reflection phase is normalized according to a 360° phase cycle to obtain a normalized phase Normalize with 1-bit phase to obtain the actual transmission phase The scattering mode operates in the radar cross-section reduction state. The scattering unit (3) is divided into four parts along the x and y axis directions from the center of the array plane, and the reflection phase states on each part are the same; the reflection phases of the four parts are sequentially set to 0°, 180°, 0°, and 180° in the clockwise direction.

[0012] Furthermore, when the array antenna is in the transmission mode, a horn antenna with an incident angle of 30° and a cross-diameter ratio of 0.6 is used as the feed source to realize a 0° focused beam propagating in the negative half-space of the z-axis; when the array antenna is in the reflection mode, a horn antenna with an incident angle of 0° and a cross-diameter ratio of 1.3 is used as the feed source to realize a 30° focused beam propagating in the positive half-space of the z-axis; when the array antenna is in the scattering mode, a plane wave is used for illumination to realize a scattering beam propagating in the positive half-space of the z-axis to reduce the radar cross-section.

[0013] Furthermore, when the number of transmission units of the array antenna is 8×8, the number of reflection units is 20×16, and the number of scattering units is 20×16, the gain of the transmission mode at 5.8 GHz is 18.6 dBi, the 3-dB gain bandwidth exceeds 31.0%, the gain of the reflection mode at 12.5 GHz is 19.1 dBi, and the -10-dB radar cross-section reduction bandwidth of the scattering mode covers 17.0 GHz to 19.3 GHz.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. A three-band common-aperture array antenna with integrated transmission, reflection, and scattering of the present invention flexibly combines planar elements and three-dimensional elements using a position staggered structure design method, realizes the transmission, reflection, and far-field scattering functions in three frequency bands respectively, expands the frequency band and beam control space of the array antenna, improves the application scenarios of the array antenna, and has the characteristics of low space occupancy, high integration, high flexibility, low cost, etc., and is easy to mass produce and widely apply.

[0016] 2. A three-band common-aperture array antenna with integrated transmission, reflection, and scattering of the present invention selects an incident angle of 30° in the transmission mode and an incident angle of 0° and an exit angle of 30° in the reflection mode to realize a reasonable distribution of the beam space, avoid the loss caused by feed source occlusion, and has the advantages of high efficiency, high performance, simple and reliable system, etc., and is suitable for modern communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art, where:

[0018] 1 - Transmitting unit, 11 - Receiving structure, 111 - Single - layer planar Vivaldi structure, 1111 - Curved slot, 1112 - First rectangular slot, 1113 - Triangular patch array, 112 - Multistage fan - shaped microstrip line, 12 - Transmitting structure, 121 - Single - layer planar octahedral structure, 1211 - Second rectangular slot, 1212 - Rectangular patch array, 122 - Differential microstrip line, 13 - Common metal ground, 14 - Metal connecting rod, 2 - Reflecting unit, 21 - Quasi - I - shaped metal step, 3 - Scattering unit, 31 - Double - slit square ring.

[0019] Figure 1 It is the front view of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment.

[0020] Figure 2 It is the top view of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment.

[0021] Figure 3 It is the model diagram of the transmitting unit of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment under four different phase states.

[0022] Figure 4 It is the model diagram of the reflecting unit of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment under two different phase states.

[0023] Figure 5 It is the model diagram of the scattering unit of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment under two different phase states.

[0024] Figure 6 It is the transmission coefficient amplitude and phase response diagram of the transmitting unit of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment under four different phase states.

[0025] Figure 7 It is the reflection coefficient amplitude and phase response diagram of the reflecting unit of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment under two different phase states.

[0026] Figure 8 It is the main polarization and cross - polarization amplitude response diagram of the scattering unit of a triple - band common - aperture array antenna with integrated transmission, reflection, and scattering as described in the embodiment.

[0027] Figure 9It is the cross-polarization reflection coefficient phase response diagram of the scattering unit of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in two different phase states described in the embodiments.

[0028] Figure 10 It is a schematic diagram of the principles of three different operating states of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering described in the embodiments.

[0029] Figure 11 It is the aperture phase distribution diagram of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in three different operating states described in the embodiments.

[0030] Figure 12 It is the gain and aperture efficiency curve diagram of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in the transmission mode described in the embodiments.

[0031] Figure 13 It is the far-field radiation pattern of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in the transmission mode described in the embodiments.

[0032] Figure 14 It is the gain and aperture efficiency curve diagram of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in the reflection mode described in the embodiments.

[0033] Figure 15 It is the far-field radiation pattern of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in the reflection mode described in the embodiments.

[0034] Figure 16 It is the radar cross-section curve diagram of a triple-band common-aperture array antenna with integrated transmission, reflection, and scattering in the scattering mode described in the embodiments. Detailed implementation manners

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] The detailed implementation manners provided by the present invention are as follows:

[0037] Please refer to Figures 1 - 5 、 Figure 10 and Figure 11, this example provides a triple-band coplanar array antenna with integrated transmission, reflection, and scattering. The array antenna includes: a transmission unit (1), the transmission unit (1) adopts a receive-transmit structure placed along the z-axis and operates in the 5.8 GHz band; the receive structure (11) of the receive-transmit structure consists of a single-layer planar Vivaldi structure (111) and a multi-stage fan-shaped microstrip line (112); the transmit structure (12) of the receive-transmit structure consists of a single-layer planar octagonal structure (121) and a differential microstrip line (122); the receive structure (11) and the transmit structure (12) are respectively placed on the front and back of a common metal ground (13) arranged along the xoy plane, and are connected through a metal connecting rod (14); a reflection unit (2), the reflection unit (2) adopts a quasi-I-shaped metal ladder (21) and operates at 12.5 GHz; a scattering unit (3), the scattering unit (3) is obtained by periodically arranging double-slit square rings, and the resonant pattern is set at the four corners of the unit and operates at 18.0 GHz; wherein, the reflection unit (2) and the scattering unit (3) have the same size and are integrated on the same square area; the integrated reflection unit (2) and scattering unit (3) are arranged on the front of the common metal ground (13) on both sides of the receive structure (11) of the transmission unit (1), and a transmission mode in the 5.8 GHz band, a reflection mode in the 12.5 GHz band, and a scattering mode in the 18.0 GHz band are realized under the coplanar condition. The single-layer planar Vivaldi structure (111) of the transmission unit (1) is a single-sided etching structure, and curve slits (1111) are arranged at both ends thereof to cut the current to achieve miniaturization; first rectangular slits (1112) are arranged at both ends of the back of the multi-stage fan-shaped microstrip line (112) of the transmission unit (1) to suppress stray current to reduce the sidelobe level; the transmission unit (1) adopts a triangular patch array (1113) with an increasing number, staggered positions, and double-sided etching along the +z direction as a director to improve the impedance matching situation within the operating frequency band to broaden the operating bandwidth; the single-layer planar octagonal structure (121) of the transmission unit (1) is a single-sided etching structure, and second rectangular slits (1211) are arranged at both ends of the bottom of the back of the differential microstrip line (122) to suppress stray current to reduce the sidelobe level; the single-layer planar octagonal structure (121) adopts a rectangular patch array (1212) with staggered positions and double-sided etching along the +z direction as a director to concentrate the electromagnetic waves along the +z direction within the operating frequency band to increase the gain.The transmission unit (1) performs a mirror operation on the multi-stage fan-shaped microstrip line (112) along the z-axis to reverse the surface current distribution of the single-layer planar Vivaldi structure (111), achieving a 180° phase change; the transmission unit (1) realizes a 90° phase change by changing the line length of the differential microstrip line (122); by simultaneously regulating the direction of the multi-stage fan-shaped microstrip line (112) and the line length of the differential microstrip line (122), 2-bit phase regulation on the y polarization is achieved. The reflection unit (2) has a phase difference of 180° between the reflection coefficient phases in the x and y polarizations; rotating the quasi-I-shaped metal ladder (21) 90° along the z-axis realizes 1-bit phase regulation in the x and y polarizations. The scattering unit (3) has a phase difference of 180° between the reflection coefficient phases in the ±45° linear polarizations; when an x- or y-polarized wave is incident on the scattering unit (3), the polarization direction of the outgoing polarized wave will rotate by 90°; mirroring the scattering unit (3) along the y-axis realizes 1-bit phase regulation in the x and y polarizations. The transmission mode operates in a beam focusing state, and the ideal transmission phase distribution of the transmission unit (1) is set as: where is the ideal transmission phase of the transmission unit (1) in the m-th row and n-th column, k t is the phase constant in vacuum, r fmn is the distance from the feed to the transmission unit (1), is the main beam direction in the transmission mode, is the direction vector from the center of the array plane to the transmission unit (1), is a constant; normalizing the ideal transmission phase according to a 360° phase cycle gives a normalized phase ranging from [0°, 360°), and normalizing it with the 2-bit phase gives the actual transmission phase The reflection mode operates in a beam focusing state, and the ideal reflection phase distribution of the reflection unit (2) is set as: where is the ideal reflection phase of the reflection unit (2) in the p-th row and q-th column, k r is the phase constant in vacuum, r fpq is the distance from the feed to the reflection unit (2), is the main beam direction in the reflection mode, is the direction vector from the center of the array plane to the reflection unit (2), is a constant; normalizing the ideal reflection phase according to a 360° phase cycle gives a normalized phase ranging from [0°, 360°), and normalizing it with the 1-bit phase gives the actual transmission phase The said scattering mode operates in the state of radar cross-section reduction. The scattering unit (3) is divided into four parts along the x and y axis directions from the center of the array surface, and the reflection phase states on each part are the same; the reflection phases of the four parts are sequentially set to 0°, 180°, 0°, and 180° in the clockwise direction. When the array antenna is in the transmission mode, a horn antenna with an incident angle of 30° and a cross-diameter ratio of 0.6 is used as the feed source to realize a 0° focused beam propagating in the negative half-space of the z axis; when the array antenna is in the reflection mode, a horn antenna with an incident angle of 0° and a cross-diameter ratio of 1.3 is used as the feed source to realize a 30° focused beam propagating in the positive half-space of the z axis; when the array antenna is in the scattering mode, it is irradiated with a plane wave to realize a scattering beam propagating in the positive half-space of the z axis to achieve the reduction of the radar cross-section. When the number of transmission units of the array antenna is 8×8, the number of reflection units is 20×16, and the number of scattering units is 20×16, the gain in the transmission mode at 5.8 GHz is 18.6 dBi, the 3-dB gain bandwidth exceeds 31.0%, the gain in the reflection mode at 12.5 GHz is 19.1 dBi, and the -10-dB radar cross-section reduction bandwidth of the scattering mode covers 17.0 GHz to 19.3 GHz.

[0038] In the present invention, the period length a and width b of the transmission unit (1) are 25.0 mm and 21.0 mm respectively; the length l1 of the receiving structure (11) and the length l2 of the transmitting structure (12) are 49.1 mm and 34.7 mm respectively, the width w is 25.0 mm, and the thickness is 1.0 mm; the thickness of the dielectric layers on the front and back sides of the common metal ground (13) is 0.5 mm; the period p of the reflection unit (2) and the scattering unit (3) is 10.0 mm; the aperture size of the array composed of 8×8 transmission units is 200.0×168.0 mm 2 .

[0039] As Figure 6 shows the transmission coefficient amplitude and phase curves of the transmission unit in four different phase states. It can be seen that near 5.8 GHz, the transmission coefficient amplitudes in the four phase states are all close to 0 dB, and the transmission phases of the states "00", "01", "10", and "11" are sequentially delayed by 90°.

[0040] As Figure 7 shows the reflection coefficient amplitude and phase curves of the reflection unit in two different phase states. It can be seen that near 12.5 GHz, the reflection coefficient amplitudes in the two phase states are all close to 0 dB, and the reflection phases of the states "0" and "1" differ by 180°.

[0041] As Figure 8The amplitude of the reflection coefficient of the main polarization and cross polarization of the scattering unit is given. It can be seen that near 18.0 GHz, the amplitude of the reflection coefficient of the main polarization is lower than -10 dB, and the amplitude of the reflection coefficient of the cross polarization is close to 0 dB, realizing that most of the incident electromagnetic waves of the main polarization are converted into cross-polarized reflected electromagnetic waves.

[0042] As Figure 9 The phase curve of the cross-polarization reflection coefficient of the scattering unit in two different phase states is given. It can be seen that near 18.0 GHz, the phases of the reflection coefficients in the two phase states maintain a 180° phase difference.

[0043] As Figure 12 The gain and aperture efficiency curves of the array antenna in the transmission mode are given. It can be seen that the array achieves the highest gain of 18.6 dBi at 5.8 GHz, and the 3-dB gain bandwidth exceeds 31.0%.

[0044] As Figure 13 The normalized far-field radiation pattern of the array antenna at 5.8 GHz is given. It can be seen that the cross-polarization level is lower than -20.0 dB, and the side lobes are lower than -8.0 dB.

[0045] As Figure 14 The gain and aperture efficiency curves of the array antenna in the reflection mode are given. It can be seen that the array achieves the highest gain of 19.1 dBi at 12.5 GHz.

[0046] As Figure 15 The normalized far-field radiation pattern of the array antenna at 12.5 GHz is given. It can be seen that the beam pointing is 29.0°, and the beam pointing error is only 1.0°.

[0047] As Figure 16 The radar cross-section curve of the array antenna in the scattering mode is given. It can be seen that the -10-dB radar cross-section reduction bandwidth covers 17.0 GHz to 19.3 GHz.

[0048] As can be seen from the above, the present invention has the characteristics of multi-function, high integration, high stability, simple and reliable system, and low cost.

[0049] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A three-band common-port array antenna integrating transmission, reflection and scattering, the array antenna comprising: A transmission unit (1), wherein the transmission unit (1) adopts a receiving-transmitting structure placed along the z-axis and operates in a 5.8 GHz frequency band; a receiving structure (11) of the receiving-transmitting structure is composed of a single-layer planar Vivaldi structure (111) and a multi-stage fan-shaped microstrip line (112); a transmitting structure (12) of the receiving-transmitting structure is composed of a single-layer planar Yagi structure (121) and a differential microstrip line (122); the receiving structure (11) and the transmitting structure (12) are respectively placed on the front and back sides of a common metal ground (13) arranged along an xoy plane, and are connected via a metal connecting rod (14); A reflection unit (2), wherein the reflection unit (2) adopts a quasi-I-shaped metal step (21) and operates in a 12.5 GHz frequency band; A scattering unit (3), wherein the scattering unit (3) is obtained by periodically forming a double-slit square ring (31), wherein resonance patterns are arranged at four corners of the unit, and the scattering unit (3) operates in the 18.0 GHz frequency band; in, The reflective unit (2) and the scattering unit (3) have the same size and are integrated on the same square area; the integrated reflective unit (2) and the scattering unit (3) are arranged on the front side of a common metal ground (13) on both sides of a receiving structure (11) of the transmission unit (1), and realize a transmission mode in the 5.8 GHz frequency band, a reflection mode in the 12.5 GHz frequency band, and a scattering mode in the 18.0 GHz frequency band under a common interface.

2. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: The single-layer planar Vivaldi structure (111) of the transmission unit (1) is a single-sided etched structure, and curved slits (1111) are arranged at both ends thereof to realize current cutting to achieve miniaturization; first rectangular slits (1112) are arranged at both ends of the back surface of the multi-stage fan-shaped microstrip line (112) of the transmission unit (1) to realize stray current suppression to reduce the side lobe level; the transmission unit (1) uses a double-sided etched triangular patch array (1113) with increasing number along the +z direction and staggered positions as a director to achieve working frequency The impedance matching condition in the segment is improved to broaden the working bandwidth; the single-layer planar Yagi structure (121) of the transmission unit (1) is a single-sided etched structure, and second rectangular slits (1211) are arranged at both ends of the bottom of the back side of the differential microstrip line (122) to suppress stray currents and reduce the side lobe level; the single-layer planar Yagi structure (121) uses a double-sided etched rectangular patch array (1212) arranged in a staggered manner along the +z direction as a director to achieve electromagnetic wave concentration along the +z direction within the working frequency band to improve gain.

3. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: The transmission unit (1) performs a mirror operation on the multi-level fan-shaped microstrip line (112) along the z-axis to achieve inversion of the surface current distribution of the single-layer planar Vivaldi structure (111), thereby achieving a 180° phase change; the transmission unit (1) achieves a 90° phase change by changing the line length of the differential microstrip line (122); and achieves 2-bit phase control on y polarization by simultaneously regulating the direction of the multi-level fan-shaped microstrip line (112) and the line length of the differential microstrip line (122).

4. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: The reflection coefficient phases of the reflection unit (2) on x and y polarizations differ by 180°; the quasi-I-shaped metal step (21) is rotated 90° along the z axis to achieve 1-bit phase regulation on x and y polarizations.

5. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: The reflection coefficient phase of the scattering unit (3) on ±45° linear polarization differs by 180°; when an x- or y-polarized wave is incident on the scattering unit (3), the polarization direction of the outgoing polarized wave will rotate by 90°; and the scattering unit (3) is mirrored along the y-axis to achieve 1-bit phase control on the x and y polarizations.

6. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: The transmission mode works in a beam focusing state, and the ideal transmission phase distribution of the transmission unit (1) is set to: in, is the ideal transmission phase of the transmission unit (1) in the mth row and nth column, k t is the phase constant in vacuum, r fmn is the distance from the feed source to the transmission unit (1), is the main beam direction in transmission mode, is the direction vector from the center of the array surface to the transmission unit (1), is a constant; the ideal transmission phase is normalized according to the phase period of 360° to obtain the normalized phase in the range of [0°, 360°) The actual transmission phase is obtained by normalizing with the 2-bit phase The reflection mode works in a beam focusing state, and the ideal reflection phase distribution of the reflection unit (2) is set to: in, is the ideal reflection phase of the reflection unit (2) in the pth row and qth column, k r is the phase constant in vacuum, r fpq is the distance from the feed source to the reflector unit (2), is the main beam direction in reflection mode, is the direction vector from the center of the array surface to the reflection unit (2), is a constant; the ideal reflection phase is normalized according to the phase period of 360° to obtain a normalized phase in the range of [0°, 360°) The actual transmission phase is obtained by normalizing with the 1-bit phase The scattering mode operates in a radar cross-section reduction state, and the scattering unit (3) is divided into four parts along the x-axis and y-axis directions from the center of the array surface, and the reflection phase state on each part is consistent; the reflection phases of the four parts are set to 0°, 180°, 0°, and 180° in sequence in the clockwise direction.

7. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: The array antenna adopts a 30° incident pyramid antenna with a cross-path ratio of 0.6 as a feed source in the transmission mode to realize a 0° focused beam propagating in the negative half space of the z-axis; the array antenna adopts a 0° incident pyramid antenna with a cross-path ratio of 1.3 as a feed source in the reflection mode to realize a 30° focused beam propagating in the positive half space of the z-axis; the array antenna adopts a plane wave for illumination in the scattering mode to realize a scattering beam propagating in the positive half space of the z-axis to achieve a reduction in the radar scattering cross section.

8. The three-band common-port array antenna integrating transmission, reflection and scattering according to claim 1, characterized in that: When the number of transmission units of the array antenna is 8×8, the number of reflection units is 20×16, and the number of scattering units is 20×16, the transmission mode gain is 18.6 dBi at 5.8 GHz, the 3-dB gain bandwidth exceeds 31.0%, the reflection mode gain is 19.1 dBi at 12.5 GHz, and the -10-dB radar scattering cross-section reduction bandwidth of the scattering mode covers 17.0 GHz to 19.3 GHz.

Images