Novel bifunctional array antenna design method based on polarized independent metasurface

Abstract

The invention belongs to the technical field of metasurface array antennas, and discloses a novel dual-function array antenna based on a polarized independent metasurface and a design method, and the novel dual-function array antenna adopts a composite metal patch with a three-layer dielectric plate structure as an upper-layer metasurface array unit; a linearly polarized microstrip antenna is adopted as a feed source and is arranged on the lower layer; the upper-layer metasurface array unit is formed by periodically arranging composite patch units with different sizes along the X and Y directions; the lower-layer structure is a microstrip antenna with a bottom coaxial port for feeding as a linear polarization feed source, and the upper-layer structure and the lower-layer structure have the same physical size and are spaced by a certain air layer height. The novel antenna is relatively simple in structure, the size is greatly reduced, and function integration of a transmission array antenna and an FP resonant cavity antenna can be achieved only through one metasurface unit. Free switching of high-gain wave beams in different radiation directions in different linear polarization working modes can be realized by changing the rotation angle of the feed source microstrip antenna.

Description

Technical Field

[0001] The present invention belongs to the technical field of metasurface array antennas, and in particular relates to a novel dual-function array antenna based on a polarization-independent metasurface and a design method thereof. Background Art

[0002] At present, the radiation function of most existing metasurface array antennas is relatively simple. They can only generate electromagnetic beams in a fixed direction under a single polarization state, and cannot generate independent electromagnetic beams in different directions in different polarization channels. Therefore, they cannot meet the flexible and changeable functional requirements of future wireless communication systems. Correspondingly, the electromagnetic wave control function of most existing metasurface units is also relatively simple. They can only realize the manipulation of the phase of electromagnetic waves, and cannot fully utilize the amplitude, phase, polarization and other characteristics of electromagnetic waves for independent and joint control, which greatly limits their application. On the other hand, the longitudinal profile height of traditional metasurface array antennas is also relatively large, and its height-to-aperture ratio is usually above 0.5, which is very unfavorable for system integration.

[0003] Metasurface is an ultra-thin structure with specific electromagnetic functions, which is composed of periodic / quasi-periodic sub-wavelength-scale units. Through the precise design of the electromagnetic response of the sub-wavelength units, the phase of the electromagnetic wave can be artificially controlled. With its advantages of low loss, high efficiency, thin thickness and strong electromagnetic control ability, metasurfaces are widely used in the design of new high-performance antennas. Generally speaking, a metasurface array antenna consists of a feed source and a metasurface array. The metasurface array is illuminated by a space feed source, and the electromagnetic wave response on the metasurface is controlled by adjusting the structural parameters of the units at different positions on the array, further achieving the required radiation performance. This new array antenna integrates the two functions of "radiation" and "phase shifting", and combines the advantages of traditional parabolic antennas and phased array antennas. It has the characteristics of low cost, easy processing, easy conformality, low profile, light weight, and no need to load complex feeding networks. In recent years, various metasurface array antennas with different structures and functions have gradually been proposed, and have broad application prospects in radar, satellite communications, and deep space exploration. However, most metasurface array antennas can only work in a specific polarization mode, and the radiation beam direction is relatively fixed. They cannot fully utilize the amplitude, phase, polarization and other characteristics of electromagnetic waves for independent and joint regulation, which limits their application scope and cannot meet the flexible and changeable functional requirements of future electronic information and communication systems. In addition, the height-aperture ratio of existing metasurface array antennas is generally above 0.5, resulting in a large longitudinal profile height, which is very unfavorable for system integration.

[0004] With the development of wireless communications in the future, electromagnetic multiplexing technology has become an important development trend for future antennas and multifunctional integrated and miniaturized systems. Antennas with dual-polarization working modes and independently controllable radiation beams have great application needs in electronic information and communication systems. Taking the wireless communication MU-MIMO system as an example, the system needs to allocate independently controlled beams to different users to meet the needs of multiple users at the same time. The metasurface array antenna with independently controlled dual-polarization beams can provide polarization diversity and spatial diversity to the MU-MIMO system, and is an antenna suitable for multi-channel multi-user systems. In addition, in order to improve the integration of communication systems, antennas are generally required to have a lower profile height. In response to the above application requirements, modern wireless communication systems urgently need a low-profile metasurface array antenna that can realize dual-polarization working modes and independently controllable radiation beams, but it is very difficult to achieve this requirement through existing methods and technologies.

[0005] Through the above analysis, the problems and defects of the prior art are as follows:

[0006] (1) Single polarization mode: Most existing metasurface array antennas can only operate in a specific polarization mode, lack flexibility, and cannot flexibly switch polarization modes in different application scenarios.

[0007] (2) Fixed beam pointing: The radiation beam pointing of existing metasurface array antennas is usually relatively fixed, which makes it impossible to flexibly control the radiation beam, limiting its application in complex environments.

[0008] (3) Limited electromagnetic wave control capability: Current antenna designs make it difficult to independently or jointly control the amplitude, phase, polarization and other characteristics of electromagnetic waves, and are unable to fully utilize the various characteristics of electromagnetic waves to meet diverse communication needs.

[0009] (4) The longitudinal profile height is relatively large: The height-aperture ratio of existing metasurface array antennas is usually above 0.5, which results in a relatively large longitudinal profile height of the antenna, affecting its integration with other systems and is not conducive to miniaturization and low-profile design requirements. Summary of the invention

[0010] In view of the problems existing in the prior art, the present invention provides a novel dual-function array antenna based on a polarization-independent metasurface and a design method.

[0011] The present invention is implemented as follows: a novel dual-function array antenna based on a polarization-independent metasurface, wherein the antenna uses a composite metal patch with a three-layer dielectric plate structure as an upper metasurface array unit; a linearly polarized microstrip antenna is used as a feed source and is placed in the lower layer;

[0012] The upper metasurface array unit is composed of composite patch units of different sizes arranged periodically along the X and Y directions; the lower structure is a microstrip antenna fed by a coaxial port at the bottom as a linearly polarized feed source, and the upper and lower structures have the same physical size and are separated by a certain air layer height.

[0013] Furthermore, the upper metasurface array can achieve full transmission of X-polarized incident waves and partial reflection of Y-polarized waves within the working frequency band, and achieve a 360° transmission phase shift variation range by adjusting the patch size of each unit in the X direction of the array.

[0014] Furthermore, by changing the height of the air layer between the upper metasurface array and the lower microstrip antenna, the antenna can realize the function of the FP resonant cavity antenna in the Y-polarization working mode and form a Y-polarization high-gain beam in the Z-axis direction;

[0015] When the antenna is in the X-polarization working mode, a phase distribution with a parabolic gradient is obtained by adjusting the patch size of each unit in the X direction of the upper metasurface array, so that the X-polarized spherical wave emitted by the feed source forms an X-polarized high-gain beam at a direction 20° away from the Z axis after being transmitted through the upper metasurface array; by adjusting the spatial rotation angle of the lower microstrip antenna, the antenna can realize free switching between the X and Y polarization working modes, thereby realizing the dual-polarization working mode of the entire antenna.

[0016] Furthermore, when the feed microstrip antenna is in the X-polarization working mode, the X-polarized wave emitted by it is incident on each unit of the upper metasurface array, and then the X-polarized incident wave penetrates each unit on the array and obtains the corresponding transmission phase compensation. Finally, the X-polarized transmission wave after phase compensation of each unit is superimposed in phase, forming a high-gain X-polarized beam in a direction deviating 20 degrees from the Z axis, thereby realizing the function of the X-polarized transmission array antenna;

[0017] When the feed microstrip antenna is in the Y-polarization working mode, the Y-polarized wave emitted by it is incident on the upper metasurface array, part of which is reflected on the metal floor of the lower microstrip antenna, while the other part of the electromagnetic wave penetrates the upper metasurface array and propagates to the outside; the reflected electromagnetic wave passes through the metal floor of the lower microstrip antenna and is incident on the upper metasurface array again, forming secondary transmission and reflection; after the electromagnetic wave undergoes the above-mentioned multiple reflections and transmissions in the upper and lower structures, it is completely radiated by the upper reflector, forming a Y-polarized high-gain beam in the Z-axis direction, realizing the function of the Y-polarized FP resonant cavity antenna.

[0018] Furthermore, the metasurface array unit is composed of three layers of dielectric plates and four layers of composite metal patch structures;

[0019] Among them, the unit period size P is 10mm, and each dielectric layer uses F4B substrateε r=2.65, thickness is t=1.5mm; each metal layer has the same square ring patch on the periphery, the width of the square ring is 0.2mm; each metal layer contains rectangular strips of the same size along the X direction, placed in the center of each layer; the bottom metal layer also contains an additional rectangular grid along the Y direction, the long side of which is connected to the square ring and the width is 2mm;

[0020] When an X-polarized wave is incident on the unit, the X-polarized wave is completely transmitted to the other side of the unit, and the phase of the Y-polarized transmitted wave is adjusted by changing the length L of the rectangular strip along the X direction inside each metal layer; when a Y-polarized wave is incident on the unit, the presence of the metal grid in the Y direction of the bottom layer has a certain blocking effect on the Y-polarized incident wave, which can mostly reflect the Y-polarized wave and transmit a small part of the Y-polarized wave.

[0021] Another object of the present invention is to provide a novel dual-function array antenna design method based on polarization-independent metasurface, comprising:

[0022] (a) Designing and constructing a composite metal patch with a three-layer dielectric plate structure as an upper metasurface array unit, wherein the unit is periodically arranged along the X and Y directions;

[0023] (b) designing and configuring the lower structure to be a linearly polarized microstrip antenna fed by a bottom coaxial port as a feed source, wherein the upper and lower structures have the same physical dimensions and are separated by a certain air layer height;

[0024] (c) The patch size of the upper metasurface array unit is adjusted to achieve a 360-degree transmission phase shift variation range, while achieving full transmission of X-polarized waves and partial reflection of Y-polarized waves.

[0025] Further, the following steps are included:

[0026] By adjusting the height of the air layer between the upper metasurface array and the lower microstrip antenna, the function of the FP resonant cavity antenna in the Y-polarization working mode is optimized to form a Y-polarization high-gain beam in the Z-axis direction;

[0027] In the X-polarization working mode, a specific phase distribution is obtained by adjusting the X-direction patch size of each unit of the upper metasurface array, so that the X-polarized spherical wave forms an X-polarized high-gain beam at a direction 20 degrees away from the Z axis.

[0028] Further, the following steps are included:

[0029] When the feed microstrip antenna is in the X-polarization working mode, the X-polarized wave is transmitted through the upper metasurface array unit and after phase compensation, an X-polarized high-gain beam is formed at a direction 20 degrees away from the Z axis;

[0030] When the feed microstrip antenna is in the Y-polarization working mode, the Y-polarized wave is partially reflected to the metal floor of the lower microstrip antenna, and after multiple reflections and transmissions, it is completely radiated by the upper reflector, forming a Y-polarized high-gain beam in the Z-axis direction, and finally realizing the function of the Y-polarized FP resonant cavity antenna.

[0031] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of a dual-function array antenna design method based on a polarization-independent metasurface.

[0032] In combination with the above technical solutions and the technical problems solved, please analyze the advantages and positive effects of the technical solutions to be protected by the present invention from the following aspects:

[0033] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, the technical solutions to be protected by the present invention and the results and data during the research and development process are closely combined to analyze in detail and deeply how the technical solutions of the present invention solve the technical problems, and some creative technical effects brought about after solving the problems. The specific description is as follows:

[0034] The present invention adopts a three-layer dielectric plate and a four-layer composite metal patch structure as the upper metasurface array unit to realize independent control of different linear polarization reflected and transmitted electromagnetic waves; a single-layer microstrip antenna is placed in the lower layer as a feed source. The designed metasurface units are arranged along the X and Y directions to form a metasurface array, and the X-polarized transmitted wave phase at different positions of the array surface is accurately compensated by reasonably adjusting the size L of each unit along the X direction, thereby realizing the transmission array antenna function in the X-polarized working mode, and generating an X-polarized high-gain beam in the direction of 20° away from the Z axis; at the same time, the continuous metal grid along the Y direction of the bottom layer of the metasurface can partially reflect the Y-polarized incident wave emitted by the feed source; by reasonably optimizing the height H of the upper metasurface array and the lower feed source antenna, the designed metasurface array antenna realizes the FP resonant cavity antenna function in the Y-polarized working mode, and generates a Y-polarized high-gain beam in the Z-axis direction. On this basis, by adjusting the spatial rotation angle of the feed microstrip antenna, the designed antenna can realize the free switching of the working modes of the X-polarized transmission array antenna and the Y-polarized FP resonant cavity antenna, thereby generating independent high-gain beams in different polarization states. Therefore, the designed new metasurface array antenna realizes the functional integration of the transmission array antenna and the FP resonant cavity antenna in different linear polarization states, and realizes the independent control of different polarized radiation beams by changing the feed rotation angle.

[0035] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by the present invention are described in detail as follows:

[0036] Traditional metasurface array antennas can only work in a certain polarization mode, and the radiation beam direction is relatively fixed. It cannot make full use of the amplitude, phase, polarization and other characteristics of electromagnetic waves for independent and joint regulation, which limits its application scope and cannot meet the flexible and changeable functional requirements of future electronic information and communication systems. In addition, the height-aperture ratio of existing metasurface array antennas is generally above 0.5, resulting in a large longitudinal section height, which is very unfavorable for system integration. In comparison, the new dual-polarization independent beam metasurface array antenna proposed in the present invention can organically integrate the functions of the transmission array antenna and the resonant cavity antenna of different linear polarizations, that is, it realizes a relatively small longitudinal section height (the height-aperture ratio is only 0.18), and realizes independent high-gain beams in different directions under different polarization states. At the same time, by adjusting the rotation angle of the feed microstrip antenna, the free switching of the functions of the X-polarization transmission array and the Y-polarization FP resonant cavity antenna is realized, thereby realizing independent control of high-gain radiation beams in different directions under different polarization states. Therefore, compared with the traditional single transmission array and resonant cavity antenna, the new dual-polarization independent beam metasurface array antenna designed by the present invention has a simple and novel structure. It does not need to use two arrays or two feed sources. It only uses a new metasurface structure and a single feed source to achieve the functional integration of two different antennas and the independent control of high-gain beams in different directions under different polarization states. In addition, the metasurface array antenna designed by the present invention achieves a relatively small longitudinal profile height, and the height-to-aperture ratio is only 0.18. Compared with most existing metasurface array antennas, the system integration is significantly improved. Therefore, the present invention proposes a new design idea for dual-polarization independent beam low-profile antennas, which provides a new technical approach and powerful method support for the future development of multi-functional and multi-polarization array antennas. The above-mentioned technical advantages are the innovative points of the present invention, so the present invention is suitable for the design of dual-polarization independent beam metasurface array antennas.

[0037] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0038] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0039] After the technical solution of the present invention is transformed, the proposed design scheme can be used to integrate the transmission array and FP resonant cavity antenna functions in different linear polarization working modes in the same metasurface array antenna, eliminating the trouble of using two antennas, significantly reducing the number of antennas in the communication system, and reducing the cost of the system. In addition, the flexible switching of the functions of the transmission array and FP resonant cavity antenna with different polarizations can be achieved by rotating the spatial rotation angle of the feed source, which significantly improves the functional integration of the metasurface array antenna and can better adapt to the flexible and changeable functional requirements of future wireless communication systems. At the same time, the height-aperture ratio of the metasurface array antenna proposed in this scheme is only 0.18, which is much lower than most existing metasurface array antennas, and can be more conducive to integration with the communication system. It also has broad application prospects in communication systems with high requirements for system integration.

[0040] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0041] The technical solution proposed in the present invention uses only a single linearly polarized feed source to realize the functions of a transmission array and FP resonant cavity antenna with independent high-gain electromagnetic beams with different beam pointing directions in different linear polarization channels, while achieving a relatively low longitudinal profile height (the height-aperture ratio is only 0.18), filling the current technical gap at home and abroad in organically integrating the functions of a transmission array and FP resonant cavity antenna with independent high-gain radiation beams with different linear polarization working modes and different beam pointing directions using a metasurface array antenna composed of a single linearly polarized feed source and a metasurface unit.

[0042] (3) Whether the technical solution of the present invention solves the technical problems that people have been eager to solve but have not been able to solve successfully:

[0043] A new metasurface unit design method is proposed that can achieve efficient transmission of X-polarized waves, 360° transmission wave phase variation range, and most reflection of Y-polarized waves, solving the technical problem of using metasurfaces to independently and jointly control the amplitude, phase, polarization and other characteristics of electromagnetic waves. At the same time, it also solves the problem of using a single linearly polarized feed source and a metasurface unit to realize a transmission array with independent high-gain radiation beams with different linear polarization working modes and different beam directions, and a low-profile dual-function array antenna with organic integration of FP resonant cavity antenna functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a functional schematic diagram of a metasurface array antenna with dual-polarization independent beam control provided by an embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of a metasurface unit structure provided by an embodiment of the present invention, wherein (a) is a side view, (b) is a top view, and (c) is a bottom view;

[0046] Figure 3 Schematic diagram of the metasurface unit provided by the embodiment of the present invention under different structural parameters, where (a) is the transmission coefficient T xx Figure, (b) is the reflection coefficient R yy Frequency variation graph;

[0047] Figure 4 Schematic diagram of the transmittance and reflection coefficients of the metasurface unit provided in an embodiment of the present invention, where (a) is T at 9 GHz xx (b) is the reflection coefficient R under different sizes L yy Frequency variation graph;

[0048] Figure 5 Schematic diagram of the metasurface unit provided by the embodiment of the present invention at different oblique incident angles, where (a) is the transmission coefficient T xx Figure, (b) is the reflection coefficient R yy Frequency variation graph;

[0049] Figure 6 1 is a diagram of the structure of an upper metasurface array provided by an embodiment of the present invention, wherein (a) is a front view and (b) is a back view;

[0050] Figure 7 is a structural diagram of a feed microstrip antenna provided by an embodiment of the present invention;

[0051] Figure 8 This is a model diagram of a dual-polarization independent beam metasurface array antenna provided by an embodiment of the present invention;

[0052] Fig. 9 : are the directional patterns of the metasurface array antenna provided by an embodiment of the present invention at different frequencies in the transmission array mode, wherein (a) is the directional pattern at a frequency of 8.5 GHz, (b) is the directional pattern at a frequency of 9 GHz, and (c) is the directional pattern at a frequency of 9.5 GHz;

[0053] Fig.10 : are the directional patterns of the metasurface array antenna provided by an embodiment of the present invention at different frequencies in the resonant cavity mode, wherein (a) is the directional pattern at a frequency of 9.8 GHz, (b) is the directional pattern at a frequency of 10 GHz, and (c) is the directional pattern at a frequency of 10.2 GHz;

[0054] Fig.11 1 is a graph showing gain variation with frequency of a metasurface array antenna provided in an embodiment of the present invention, wherein (a) is a graph showing gain variation with frequency in a transmission array working mode, and (b) is a graph showing gain variation with frequency in a resonant cavity working mode;

[0055] Fig.12It is a curve diagram of gain variation with frequency of the linear polarization feed microstrip antenna provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] 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.

[0057] 1. Explanatory Examples In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an illustrative example that expands and describes the technical solution of the claims.

[0058] The novel metasurface array antenna with dual-polarization independent beam control function designed by the present invention is characterized by: using a composite metal patch with a three-layer dielectric plate structure as an upper metasurface array unit; using a linearly polarized microstrip antenna as a feed source and placed in the lower layer. Among them, the upper metasurface array is composed of a series of composite patch units of different sizes arranged periodically along the X and Y directions, and the lower structure is a microstrip antenna fed by the bottom coaxial port as a linearly polarized feed source. The upper and lower structures have the same physical size and are separated by a certain air layer height. The upper metasurface array can achieve full transmission of X-polarized incident waves and partial reflection of Y-polarized waves within the working frequency band, and achieve a 360° transmission phase shift variation range by adjusting the patch size of each unit in the X direction of the array. By reasonably designing and optimizing the air layer height between the upper metasurface array and the lower microstrip antenna, the antenna can realize the FP resonant cavity antenna function in the Y-polarization working mode and form a Y-polarized high-gain beam in the Z-axis direction. When the antenna is in the X-polarization working mode, a specific phase distribution is obtained by adjusting the patch size of each unit in the X direction of the upper metasurface array, thereby ensuring that the X-polarized spherical wave emitted by the feed source forms an X-polarized high-gain beam at a direction 20° away from the Z axis after being transmitted through the upper metasurface array; by adjusting the spatial rotation angle of the lower microstrip antenna, the antenna can realize the free switching of the X- and Y-polarization working modes, thereby ensuring the dual-polarization working mode of the entire antenna. The functional schematic diagram of the new metasurface array antenna with dual-polarization independent beam control designed by the present invention is shown in FIG. Figure 1 shown.

[0059] The working mechanism of the antenna is as follows:

[0060] (1) When the feed microstrip antenna is in the X-polarization working mode, the X-polarized wave emitted by it is incident on each unit of the upper metasurface array, and then the X-polarized incident wave penetrates each unit on the array and obtains the corresponding transmission phase compensation. Finally, the X-polarized transmitted wave after phase compensation of each unit is superimposed in phase, forming a high-gain X-polarized beam in a direction deviating 20 degrees from the Z axis, thereby realizing the function of the X-polarized transmission array antenna;

[0061] (2) When the feed microstrip antenna is in the Y-polarization working mode, the Y-polarized wave emitted by it is incident on the upper metasurface array, part of which is reflected on the metal floor of the lower microstrip antenna, while the other part of the electromagnetic wave penetrates the upper metasurface array and propagates to the outside. The reflected electromagnetic wave passes through the metal floor of the lower microstrip antenna and is incident on the upper metasurface array again, forming secondary transmission and reflection. After the electromagnetic wave undergoes the above-mentioned multiple reflections and transmissions in the upper and lower structures, it is completely radiated by the upper reflector, forming a Y-polarized high-gain beam in the Z-axis direction, thereby realizing the function of the Y-polarized FP resonant cavity antenna.

[0062] from Figure 1 It can be seen that in order to make the designed metasurface array antenna realize the function of transmission array antenna in the X-polarization working mode, the designed upper metasurface is required to be able to transmit X-polarized waves and realize arbitrary control of their phase; in order to make the designed metasurface antenna realize the function of FP resonant cavity antenna in the Y-polarization working mode, the upper metasurface is required to be able to reflect most of the Y-polarization waves and transmit a small part of the Y-polarization waves.

[0063] In order to achieve Figure 1 The function of the upper metasurface array shown in FIG. 1 is as follows: Figure 2 As shown:

[0064] from Figure 2 It can be seen that the unit is composed of three layers of dielectric plates and four layers of composite metal patch structures. Among them, the unit period size P is 10mm, and each dielectric layer uses F4B substrate (ε r=2.65), with a thickness of t=1mm; each metal layer has the same square ring patch on the periphery, and the width of the square ring is 0.2mm; each metal layer contains rectangular strips of the same size along the X direction, which are placed in the center of each layer. In addition, the bottom metal layer also contains an additional rectangular grid along the Y direction, the long side of which is connected to the square ring and has a width of 2mm. When the X-polarized wave is incident on the unit, it can be completely transmitted to the other side of the unit, and the phase of the Y-polarized transmitted wave can be adjusted by changing the length L of the rectangular strip along the X direction inside each metal layer. When the Y-polarized wave is incident on the unit, the presence of the metal grid in the Y direction of the bottom layer has a certain blocking effect on the Y-polarized incident wave, which can mostly reflect the Y-polarized wave and transmit a small part of the Y-polarized wave. It should be noted that since the rectangular strips of the unit along the X direction are orthogonal to the rectangular grids of the bottom layer along the Y direction, this layout method enables the X and Y polarized working modes of the unit to have good isolation, and the cross coupling is minimized. Therefore, by using this unit to design a metasurface array antenna, the functions of the X-transmission array antenna and the Y-polarized FP resonant cavity antenna will not affect each other, thereby ensuring the realization of independent high-gain beams in different polarization working modes. Figure 3 (a) shows the X-polarization transmission coefficient T of the unit at different L sizes when the X-polarization incident wave is incident vertically. xx The amplitude and phase change curves with frequency. It can be seen that when L changes from 5mm to 6mm, T xx The amplitude in the range of 8-12GHz is always above -2dB; at the same time, the phase variation range of the unit under different L sizes is always above 360°. The results show that with the change of L size, the unit can have good transmission characteristics for X-polarized waves in a wide band. Figure 3 (b) The Y-polarization reflection coefficient R of the unit under different Y-direction rectangular grid widths G is given when the unit is vertically illuminated by a Y-polarized incident wave. yy The curve of amplitude and phase changing with frequency. It can be seen that when G changes from 1mm to 3mm, the reflection coefficient R yy The amplitude gradually increases in the entire frequency band and always remains above -2dB, and the amplitude at the central operating frequency of 9.5GHz changes from -1dB to -0.2dB. yy The phase curves are approximately parallel. From the results in the figure, it can be found that the unit has the characteristic of reflecting most of the Y-polarized waves within the working frequency band. Figure 4 (a) shows the X-polarization transmission coefficient T of the unit at an operating frequency of 9 GHz. xx The curves of amplitude and phase changing with size L. As can be seen from the figure, when L is in the range of 1 to 9 mm, T xxThe amplitude is above -1dB, and the phase change range is above 360°. Therefore, the design unit maintains high transmittance for X-polarized waves at different L sizes, and the phase shift range of X-polarized transmitted waves above 360° can be obtained by changing the structural parameter L. Figure 4 (b) The Y-polarization reflection coefficient R of the unit at different sizes L is given yy The amplitude and phase change curves with frequency. It can be seen that as L changes from 4mm to 7mm, the reflection coefficient R yy The amplitude gradually increases and always remains above -0.8dB. At the same time, R yy The phase curve remains almost unchanged in the entire frequency band. The results show that the change of L size has little effect on the Y polarization reflection performance, which further indicates that the X and Y polarization working modes of the unit do not affect each other, and the polarization crosstalk between them is very small. xx , R yy The amplitude and phase curves of the frequency are as follows: Figure 5 (a) and (b). Figure 5 (a) It can be seen that with the oblique incident angle θ i From 0° to 45°, the fluctuation of the Txx amplitude curve of the unit at the same frequency in the range of 7.5-11.5GHz does not exceed 1.5dB; at the same time, the Txx phase curve is approximately parallel. Figure 5 (b) It can also be seen that the Rxx amplitude of the unit is always above -1dB within the range of oblique incident angle less than 45°, and the phase fluctuation at the same frequency is less than 30°. The above results show that the metasurface unit proposed in the present invention can achieve high transmittance in a wide band for X-polarized incident waves, and achieve a phase shift range of more than 360° by adjusting the length value L of the rectangular strip in the X direction; while for Y-polarized incident waves, most of the reflection and a small part of the transmission can be achieved. At the same time, its X-polarized transmission and Y-polarized reflection performances remain basically stable within the range of oblique incident angle less than 45°. On this basis, by reasonably setting the air layer height of the upper metasurface and the lower feed microstrip antenna, the function of the Y-polarized FP resonant cavity antenna can be realized, and a Y-polarized high-gain beam can be formed in the Z-axis direction; by adjusting the length value L of the rectangular strips of each unit on the metasurface, a specific transmission phase distribution can be formed on the metasurface, realizing the function of the X-polarized transmission array antenna, and an X-polarized high-gain radiation beam at a direction 20° away from the Z axis.

[0065] In order to realize the transmission array antenna function in the X-polarization working mode, the present invention designs an upper metasurface array composed of metasurface units of different sizes arranged in the X and Y directions, consisting of 15×15 units, and the corresponding size is 150mm×150mm (D=150mm). Considering the functional realization of the FP resonant cavity antenna in the Y-polarization working mode, through careful design and optimization, the air layer height H between the upper metasurface array and the lower feed antenna is set to 27mm, and the corresponding height-to-aperture ratio is H / D=0.18.

[0066] Since the microstrip antenna has the advantages of side-firing, low profile, simple structure, easy processing and low cost, the present invention adopts the microstrip antenna as the feed antenna of the dual-polarization independent beam metasurface array. Figure 7 The microstrip antenna is fed from the bottom of the coaxial port, and the size of the rectangular patch in the center is 10mm×7.2mm.

[0067] On this basis, the metasurface array is placed on the top and the microstrip antenna is placed on the bottom as the feed source, and the following is obtained: Figure 8 The dual-polarization independent beam metasurface array antenna model shown. The upper metasurface array and the lower feed microstrip antenna of the antenna have the same size, the longitudinal section height H between the upper and lower structures is 27 mm, and the corresponding height-to-aperture ratio is 0.18. When the feed microstrip antenna operates in X-polarization, the designed metasurface antenna can realize the transmission array function, forming a high-gain X-polarization beam in the direction 20° away from the Z axis; the feed microstrip antenna is rotated 90°, and its polarization mode is converted to Y polarization. At this time, the designed antenna can realize the FP resonant cavity antenna function, forming a high-gain Y-polarization beam in the Z-axis direction. Therefore, the metasurface array antenna designed by the present invention can realize dual polarization, high directivity and independent beam control, and flexible switching of different working modes can be achieved by adjusting the spatial rotation angle of the feed.

[0068] Fig. 9 The normalized radiation patterns of the metasurface array antenna at different frequencies are given when the feed microstrip antenna works in the X-polarization state. It can be seen that the radiation patterns at 8.5, 9, and 9.5 GHz have good consistency, and the radiation beams are all pointed in the direction of about 20° away from the Z axis. Fig.10 The normalized radiation patterns of the metasurface array antenna at different frequencies in the xoz plane are given when the feed microstrip antenna is rotated 90° (i.e., working in the Y polarization state). It can be seen that the radiation patterns at 9.8, 10, and 10.2 GHz also have good consistency, and the radiation beam directions are all in the direction of the Z axis (0°). Fig.11 The gain-frequency curves of the antenna in different working modes are given. Fig.10(a) It can be seen that when the antenna works in the X-polarization transmission array mode, the gain reaches a peak value of about 20dBi at 9.2GHz; the corresponding aperture efficiency is about 38%. At the same time, the frequency band range of its 3-dB gain bandwidth is about 8.4-9.6GHz. Fig.10 (b) It can be seen that when the antenna works in the Y-polarized FP resonant cavity mode, the gain at 9.9GHz reaches a peak value of about 20.1dBi; the corresponding aperture efficiency is about 33%, and the frequency band range of its 3-dB gain bandwidth is about 9.8-10.1GHz. The above results show that the designed metasurface array antenna can realize high-gain radiation beams with different linear polarizations and different directions within the working frequency band, and the independent control of high-gain radiation beams with different linear polarizations and different directions can be achieved by reasonably adjusting the rotation angle of the feed microstrip antenna, thereby verifying the effectiveness of the present invention. Furthermore, the dual-polarized independent beam metasurface array antenna proposed in the present invention only uses a metasurface structure and a single feed source to realize the organic integration of the functions of the transmission array antenna and the resonant cavity antenna, and well compensates for the limitations of the single operation of the two antennas, and realizes the independent control of high-gain radiation beams in different directions under different polarization states. The antenna structure is simple and novel. Compared with the traditional metasurface array antenna, its longitudinal section height is significantly lower, and the system integration is significantly improved.

[0069] 2. Application Examples: In order to prove the creativity and technical value of the technical solution of the present invention, this section provides application examples of the technical solution of the claims on specific products or related technologies.

[0070] Example 1: Dual-polarized metasurface array antenna in a radar system

[0071] In the radar system, the antenna is required to be able to simultaneously receive and transmit X-polarized and Y-polarized electromagnetic waves to improve the accuracy of target recognition and anti-interference ability.

[0072] The dual-function metasurface array antenna of the present invention is composed of a metasurface array on the upper layer and a microstrip antenna feed on the lower layer. The microstrip antenna in the radar system is used as a feed source. When working in the X-polarization mode, the emitted X-polarized electromagnetic waves are incident on the metasurface array unit on the upper layer. Each unit adjusts the transmission phase according to the designed patch size, so that the transmitted X-polarized wave forms a high-gain beam in a direction deviating 20 degrees from the Z axis, thereby effectively covering the target area.

[0073] In the Y-polarization mode, part of the Y-polarized electromagnetic wave emitted by the microstrip antenna is reflected by the upper metasurface array, and the other part is transmitted. The reflected wave is incident on the metasurface array unit again, and undergoes multiple reflections and transmissions, and finally forms a high-gain Y-polarized beam in the Z-axis direction. The flexible switching of this dual-polarization working mode enables the radar system to adapt to different detection needs and improves the comprehensive performance of the radar system.

[0074] Embodiment 2: Dual-polarized metasurface array antenna in MU-MIMO wireless communication system

[0075] In a multi-user multiple-input multiple-output (MU-MIMO) wireless communication system, the system needs to allocate independent beams to different users and use polarization diversity and spatial diversity to improve communication efficiency.

[0076] The metasurface array antenna of the present invention realizes independent control of X-polarized and Y-polarized beams through the structural design of the upper metasurface array. In the X-polarized mode, the system can generate X-polarized beams with different phase distributions by adjusting the X-direction patch size of the metasurface array to distribute to different users. The deviation direction of this beam can be adjusted by design, so that multiple users can obtain high-quality signal transmission at the same time.

[0077] In the Y-polarization mode, by adjusting the height of the air layer and utilizing the FP resonant cavity effect, the antenna can generate a high-gain Y-polarization beam in the Z-axis direction, further increasing the spatial diversity effect. The low-profile design of the antenna also makes it easier to integrate into portable communication devices, effectively improving the system's integration and miniaturization.

[0078] 3. Evidence of the effects of the embodiments. The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the prior art. The following content is described in conjunction with the data, charts, etc. of the test process.

[0079] The novel dual-function metasurface array antenna designed in the present invention can effectively integrate the functions of the transmission array and FP resonant cavity antenna of different linear polarizations under the same array aperture. It only uses one metasurface unit and a single single-linear polarization feed microstrip antenna. It can achieve positive effects such as low profile, independent high-gain beams with different polarizations and different radiation directions, and independent beams of different polarizations can be flexibly and freely switched.

[0080] Figure 8 The designed antenna structure is given. Figure 8It can be seen that the longitudinal section height of the antenna is H, where the value of H is 27mm; the array aperture size D = 150mm, so the height-to-aperture ratio of the metasurface array antenna is H / D = 0.18. However, the height-to-aperture ratio of most conventional transmission array antennas currently available is usually above 0.5. Therefore, compared with most conventional transmission array antennas, the new dual-function metasurface array antenna designed in the present invention has achieved a positive effect of significantly reducing the section height. In addition, from Figure 8 It can also be seen that the antenna only uses a single linear polarization microstrip antenna as a feed source and uses a metasurface unit structure. Therefore, the structure of the antenna is relatively simple. Using only a single linear polarization feed source and a metasurface unit structure, it can achieve the positive effect of realizing the functions of two antennas, namely, a transmission array and a FP resonant cavity antenna.

[0081] In order to illustrate the positive effect that the novel dual-function metasurface array antenna designed by the present invention obtains independent high-gain beams with different polarizations and different radiation directions and the independent beams with different polarizations can be flexibly and freely switched, Fig. 9 The normalized radiation patterns of the metasurface array antenna at different frequencies are given when the feed microstrip antenna works in the X-polarization state. It can be seen that the radiation patterns at 8.5, 9, and 9.5 GHz have good consistency, and the radiation beams are all pointed in the direction of about 20° away from the Z axis. This shows that when the feed works in the X-polarization state, the metasurface antenna can realize the function of a transmission array antenna, and can form independent high-gain electromagnetic beams that are about 20° away from the Z axis at different frequencies. Fig.10 The normalized radiation patterns of the xoz plane of the metasurface array antenna at different frequencies are given when the feed microstrip antenna is rotated 90° (i.e., working in the Y-polarization state). It can be seen that the radiation patterns at 9.8, 10, and 10.2 GHz are also very consistent, and the radiation beam directions are all in the Z-axis direction (0°). This shows that when the feed source works in the Y-polarization state, the metasurface antenna can realize the function of the FP resonant cavity antenna and can form independent high-gain electromagnetic beams in the Z-axis direction (0°) at different frequencies. Fig.11 The gain-frequency curves of the antenna in different working modes are given. Fig.11 (a) It can be seen that when the antenna works in the X-polarization transmission array mode, the gain reaches a peak value of about 20dBi at 9.2GHz; the corresponding aperture efficiency is about 38%. At the same time, the frequency band range of its 3-dB gain bandwidth is about 8.4-9.6GHz. Fig.11(b) It can be seen that when the antenna works in the Y-polarized FP resonant cavity mode, the gain reaches a peak value of about 20.1dBi at 9.9GHz; the corresponding aperture efficiency is about 33%, and the frequency band range of its 3-dB gain bandwidth is about 9.8-10.1GHz. The above results show that the designed metasurface array antenna can achieve high-gain radiation beams with different linear polarizations and different directions within the working frequency band, and can achieve positive effects such as independent control of high-gain radiation beams with different linear polarizations and different directions by reasonably adjusting the rotation angle of the feed microstrip antenna.

[0082] In order to illustrate the positive effect of high gain achieved by the dual-function metasurface array antenna designed by the present invention, Fig.12 A curve diagram showing the gain variation with frequency of the linear polarization feed microstrip antenna used in the present invention is provided. Fig.12 The experimental results show that the gain of the linearly polarized feed microstrip antenna is 6.5-7.2dB at 8-10.5GHz; Fig.11 The experimental results of (a) show that the designed metasurface array antenna has a gain of about 14.5-20dB at 8-10GHz in the X-polarization working mode. Compared with a single-feed microstrip antenna, the designed metasurface array antenna has a net gain increase of at least 8dB in the X-polarization working mode. Fig.11 The test results of (b) show that the designed metasurface array antenna has a gain of about 16-20.1 dB at 9.8-10.2 GHz in the Y-polarization working mode. Compared with a single-feed microstrip antenna, the designed metasurface array antenna has a net gain increase of at least 9 dB in the Y-polarization working mode. Therefore, the metasurface array antenna designed by the present invention achieves a positive effect of high gain in both X and Y polarization working modes.

[0083] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0084] 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 modification, equivalent substitution and improvement 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 within the protection scope of the present invention.

Claims

1. A novel dual-function array antenna based on polarization-independent metasurface, characterized in that: The antenna uses a composite metal patch with a three-layer dielectric plate structure as an upper metasurface array unit; a linearly polarized microstrip antenna is used as a feed source and is placed in the lower layer; The upper metasurface array unit is composed of composite patch units of different sizes arranged periodically along the X and Y directions; the lower structure is a microstrip antenna fed by a coaxial port at the bottom as a linearly polarized feed source, and the upper and lower structures have the same physical size and are separated by a certain air layer height.

2. The novel dual-function array antenna based on polarization-independent metasurface according to claim 1, characterized in that: The upper metasurface array can achieve full transmission of X-polarized incident waves and partial reflection of Y-polarized waves within the working frequency band, and achieve a 360° transmission phase shift variation range by adjusting the patch size of each unit in the X direction of the array.

3. The novel dual-function array antenna based on polarization-independent metasurface according to claim 1, characterized in that: By changing the height of the air layer between the upper metasurface array and the lower microstrip antenna, the antenna can realize the function of the FP resonant cavity antenna in the Y-polarization working mode and form a Y-polarization high-gain beam in the Z-axis direction; When the antenna is in the X-polarization working mode, a phase distribution with a parabolic gradient is obtained by adjusting the patch size of each unit in the X direction of the upper metasurface array, so that the X-polarized spherical wave emitted by the feed source forms an X-polarized high-gain beam at a direction 20° away from the Z axis after being transmitted through the upper metasurface array; by adjusting the spatial rotation angle of the lower microstrip antenna, the antenna can realize free switching between the X and Y polarization working modes, thereby realizing the dual-polarization working mode of the entire antenna.

4. The novel dual-function array antenna based on polarization-independent metasurface according to claim 3, characterized in that: When the feed microstrip antenna is in the X-polarization working mode, the X-polarized wave emitted by it is incident on each unit of the upper metasurface array, and then the X-polarized incident wave penetrates each unit on the array and obtains the corresponding transmission phase compensation. Finally, the X-polarized transmission wave after phase compensation of each unit is superimposed in phase, forming a high-gain X-polarized beam in the direction deviating 20 degrees from the Z axis, thereby realizing the function of the X-polarized transmission array antenna; When the feed microstrip antenna is in the Y-polarization working mode, the Y-polarized wave emitted by it is incident on the upper metasurface array, part of which is reflected on the metal floor of the lower microstrip antenna, while the other part of the electromagnetic wave penetrates the upper metasurface array and propagates to the outside; the reflected electromagnetic wave passes through the metal floor of the lower microstrip antenna and is incident on the upper metasurface array again, forming secondary transmission and reflection; after the electromagnetic wave undergoes the above-mentioned multiple reflections and transmissions in the upper and lower structures, it is completely radiated by the upper reflector, forming a Y-polarized high-gain beam in the Z-axis direction, realizing the function of the Y-polarized FP resonant cavity antenna.

5. The novel dual-function array antenna based on polarization-independent metasurface according to claim 1, characterized in that: The metasurface array unit is composed of three layers of dielectric plates and four layers of composite metal patch structures; Among them, the unit period size P is 10mm, and each dielectric layer uses F4B substrateε r =2.65, thickness is t=1mm; each metal layer has the same square ring patch on the periphery, the width of the square ring is 0.2mm; each metal layer contains rectangular strips of the same size along the X direction, placed in the center of each layer; the bottom metal layer also contains an additional rectangular grid along the Y direction, the long side of which is connected to the square ring and the width is 2mm; When an X-polarized wave is incident on the unit, the X-polarized wave is completely transmitted to the other side of the unit, and the phase of the Y-polarized transmitted wave is adjusted by changing the length L of the rectangular strip along the X direction inside each metal layer; when a Y-polarized wave is incident on the unit, the presence of the metal grid in the Y direction of the bottom layer has a certain blocking effect on the Y-polarized incident wave, which can mostly reflect the Y-polarized wave and transmit a small part of the Y-polarized wave.

6. A novel dual-function array antenna design method based on a polarization-independent metasurface of the antenna as claimed in claim 1, characterized in that: include: (a) Designing and constructing a composite metal patch with a three-layer dielectric plate structure as an upper metasurface array unit, wherein the unit is periodically arranged along the X and Y directions; (b) designing and configuring the lower structure to be a linearly polarized microstrip antenna fed by a bottom coaxial port as a feed source, wherein the upper and lower structures have the same physical dimensions and are separated by a certain air layer height; (c) The patch size of the upper metasurface array unit is adjusted to achieve a 360-degree transmission phase shift variation range, while achieving full transmission of X-polarized waves and partial reflection of Y-polarized waves.

7. The dual-function array antenna design method based on polarization-independent metasurface according to claim 6, characterized in that: Further comprising the steps of: By adjusting the height of the air layer between the upper metasurface array and the lower microstrip antenna, the function of the FP resonant cavity antenna in the Y-polarization working mode is optimized to form a Y-polarization high-gain beam in the Z-axis direction; In the X-polarization working mode, a specific phase distribution is obtained by adjusting the X-direction patch size of each unit of the upper metasurface array, so that the X-polarized spherical wave forms an X-polarized high-gain beam at a direction 20 degrees away from the Z axis.

8. The dual-function array antenna design method based on polarization-independent metasurface according to claim 6, characterized in that: Further comprising the steps of: When the feed microstrip antenna is in the X-polarization working mode, the X-polarized wave is transmitted through the upper metasurface array unit and after phase compensation, an X-polarized high-gain beam is formed at a direction 20 degrees away from the Z axis; When the feed microstrip antenna is in the Y-polarization working mode, the Y-polarized wave is partially reflected to the metal floor of the lower microstrip antenna, and after multiple reflections and transmissions, it is completely radiated by the upper reflector, forming a Y-polarized high-gain beam in the Z-axis direction, and finally realizing the function of the Y-polarized FP resonant cavity antenna.

9. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the dual-function array antenna design method based on polarization-independent metasurface as described in claim 6.

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