A high aperture efficiency terahertz antenna

Abstract

This invention discloses a high-aperture-efficiency terahertz antenna, comprising: a metal resonant cavity unit, which includes a metal feed layer and a metal resonant layer stacked sequentially, wherein the metal resonant layer has a resonant through slot; and a metasurface structure unit stacked and connected to the surface of the metal resonant layer, the metasurface structure unit including a first metal layer, a dielectric substrate, and a second metal layer stacked sequentially connected to the surface of the metal resonant layer, wherein a hollow position is formed in the center of the second metal layer, and an M-row N-column metasurface reflector component is disposed within the hollow position, where M and N are both 5-7. Based on the metal feed layer and the metasurface structure unit with the dielectric substrate, this antenna achieves high aperture efficiency and high gain in the terahertz band, stable beam performance, a simple and highly integrated antenna structure, and high circular polarization conversion efficiency, meeting the requirements of long-distance communication.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology and relates to an antenna, specifically a high-aperture-efficiency terahertz antenna. Background Technology

[0002] With the continuous advancement of informatization, intelligentization, and interconnectivity, and to meet the development needs of communication and radar, as well as with a deeper understanding of electromagnetic waves, the high-frequency electromagnetic spectrum has been developed and utilized in recent years. Communication and radar frequencies have evolved from microwaves to millimeter waves and terahertz waves. Terahertz waves (THz) typically refer to electromagnetic waves with frequencies ranging from 0.1 THz to 10 THz, falling between microwaves and infrared light. As wireless communication evolves towards sixth-generation mobile communication (6G), terahertz technology, due to its enormous available bandwidth, has become a key candidate technology for achieving Tbit / s-level ultra-high-speed data transmission. As the front end of a wireless transceiver system, the performance of a terahertz antenna directly determines the quality of the entire communication link.

[0003] Due to the significant transmission losses in the millimeter-wave and terahertz bands, it is difficult to meet the requirements for efficient transmission, thus significantly increasing the performance requirements for antennas. This primarily involves higher requirements for aperture utilization and antenna gain. In traditional low-frequency antenna design, to ensure excellent performance within the required operating frequency domain, many complex feeding structures are often introduced. This is difficult to achieve in the terahertz band because the short wavelength of terahertz waves demands extremely high precision in the fabrication of the structures.

[0004] To address the aforementioned technical challenges, space-fed resonant cavity antennas suitable for the terahertz band have emerged. Among these, the Fabry-Perot cavity antenna is a typical example capable of achieving high gain, and its simple structure has garnered widespread attention. For application in the terahertz band, all-metal Fabry-Perot cavity antennas have become an important development direction. Fabry-Perot cavity antennas made entirely of metal offer high efficiency, high reliability, and ease of maintenance in the terahertz band. However, their metal structure is difficult to cut and process, and its complex design limits the flexibility of adjusting the antenna structure to achieve superior performance. Furthermore, their high manufacturing difficulty and cost make them unsuitable for the communication demands of the terahertz band.

[0005] In view of this, it is necessary to further improve the existing terahertz antennas. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is that the existing Fabry-Perot cavity antennas used in the terahertz band are complex in structure, difficult to process, have high manufacturing cost, and cannot meet the performance requirements of the terahertz band. Therefore, the present invention proposes a high-efficiency terahertz Fabry-Perot cavity antenna that is simple in structure, easy to process, low in cost, and has excellent performance.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: This invention provides a high-aperture-efficiency terahertz antenna, comprising: A metal resonant cavity unit includes a metal feed layer and a metal resonant layer stacked sequentially, wherein the metal resonant layer has a resonant through slot; A metasurface structure unit is stacked and connected to the surface of the metal resonant layer. The metasurface structure unit includes a first metal layer, a dielectric substrate, and a second metal layer sequentially connected to the surface of the metal resonant layer. A cutout is formed in the center of the second metal layer, and an M-row N-column metasurface reflective component is arranged in the cutout, where M and N are both 5-7.

[0008] Preferably, a metal ground layer is provided between the metal feed layer and the metal resonant layer, and the metal ground layer has a ground channel that is connected to the resonant channel.

[0009] Preferably, at least one metal impedance matching layer is provided between the metal feed layer and the metal ground layer, and the metal impedance matching layer has a matching layer gap structure.

[0010] Preferably, the metasurface reflective component includes a bottom metal layer, a dielectric layer, and a top metal layer stacked sequentially. The bottom metal layer is connected to the dielectric substrate, the top metal layer has a top gap, and the bottom metal layer has a bottom gap. The length and width of the outer periphery of the metasurface reflective component are both 0.3λ0-0.45λ0, and the spacing between adjacent metasurface reflective components is 0.3λ0-0.45λ0, where λ0 is the wavelength at the antenna operating frequency.

[0011] Preferably, the dielectric layer is a cuboid plate structure with a thickness of 0.08λ0-0.12λ0; the top metal has a hexagonal cross-section and is obtained by removing a set of diagonals from a rectangular metal sheet with a length and width of 0.2λ0-0.35λ0; the top gap is a rectangular gap located in the center of the top metal and extending along the diagonal of the dielectric layer, with a length of 0.1λ0-0.2λ0 and a width of 0.045λ0-0.065λ0; the bottom metal is a rectangular metal layer with the same length and width as the dielectric layer, and the bottom gap is a rectangular gap located in the center of the bottom metal, with a length of 0.25λ0-0.3λ0 and a width of 0.045λ0-0.065λ0.

[0012] Preferably, the metal resonant layer is a cuboid plate structure with a length and width of 3λ0-10λ0 and a thickness of 0.41λ0-0.51λ0; a resonant through slot with a length and width of 2.15λ0-2.25λ0 is formed in the center of the metal resonant layer; the metal feed layer is a cuboid plate structure with the same length and width as the metal resonant layer, and a thickness of 0.3λ0-1λ0, where λ0 is the wavelength at the antenna operating frequency.

[0013] Preferably, the metal ground layer is a cuboid plate structure, with its length and width being the same as those of the metal resonant layer, and its thickness being 0.06λ0-0.08λ0. A trapezoidal platform-shaped ground channel is formed in the center of the metal ground layer. The upper bottom length and width of the ground channel are the same as those of the resonant channel, and the lower bottom length of the ground channel is 0.95λ0-1.05λ0, and its width is 0.75λ0-0.85λ0.

[0014] Preferably, the metal impedance matching layer includes a first impedance matching layer, a second impedance matching layer, a third impedance matching layer and a fourth impedance matching layer stacked sequentially in a direction away from the metal ground layer. The length and width of the metal impedance matching layer are the same as the length and width of the metal resonant layer, respectively, and the thickness is 0.95λ0-1.05λ0.

[0015] Preferably, the first impedance matching layer has a first matching layer gap and a second matching layer gap spaced apart at its center. The length of the first matching layer gap and the second matching layer gap are 0.83λ0-0.93λ0, the width is 0.41λ0-0.51λ0, and the distance between the first matching layer gap and the second matching layer gap is 0.1λ0-0.2λ0. The second impedance matching layer has a third matching layer gap spaced apart at its center. The third impedance matching layer has a fourth matching layer gap and a fifth matching layer gap spaced apart at its center. The fourth and fifth matching layer gaps have a length of 0.45λ0-0.55λ0 and a width of 0.28λ0-0.38λ0, and the distance between the fourth and fifth matching layer gaps is 0.02λ0-0.12λ0. A sixth and seventh matching layer gap are spaced apart in the center of the fourth impedance matching layer. The sixth and seventh matching layer gaps have a length of 0.83λ0-0.93λ0 and a width of 0.46λ0-0.56λ0, and the distance between the sixth and seventh matching layer gaps is 0.13λ0-0.23λ0.

[0016] Preferably, the metal feed layer, metal impedance matching layer, metal ground layer, metal resonant layer, and metasurface structure unit are fixedly connected by a screw array, wherein the distance between each screw and the metasurface structure unit is greater than 1λ0; the metal feed layer is also connected to an adapter.

[0017] The technical solution of the present invention has the following advantages compared with the prior art: The high-aperture-efficiency terahertz antenna provided by this invention includes: a metal resonant cavity unit, comprising a metal feed layer and a metal resonant layer stacked sequentially, wherein the metal resonant layer has a resonant through slot; and a metasurface structure unit stacked and connected to the surface of the metal resonant layer, the metasurface structure unit comprising a first metal layer, a dielectric substrate, and a second metal layer stacked sequentially connected to the surface of the metal resonant layer, wherein a hollow position is formed in the center of the second metal layer, and an M-row N-column metasurface reflector component is disposed within the hollow position, where M and N are both 5-7. Based on the metal feed layer and the metasurface structure unit with the dielectric substrate, this antenna achieves high aperture efficiency and high gain in the terahertz band, stable beam performance, a simple and highly integrated antenna structure, and high circular polarization conversion efficiency, meeting the requirements of long-distance communication. Attached Figure Description

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1This is a schematic diagram of the structure of the high-aperture efficiency terahertz antenna provided in an embodiment of the present invention; Figure 2 This is a side view of the high-aperture efficiency terahertz antenna provided in an embodiment of the present invention; Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle; Figure 4 This is an exploded schematic diagram of the metal resonant layer and the metal ground layer in the high-aperture efficiency terahertz antenna provided in the embodiment of the present invention; Figure 5 This is an exploded schematic diagram of the metallic impedance matching layer in the high-aperture efficiency terahertz antenna provided in an embodiment of the present invention; Figure 6 This is a side view of the metasurface reflector component in the high-aperture efficiency terahertz antenna provided in an embodiment of the present invention; Figure 7 This is a top view of the metasurface reflector component in the high-aperture efficiency terahertz antenna provided in an embodiment of the present invention; Figure 8 This is a bottom view of the metasurface reflector component in the high-aperture efficiency terahertz antenna provided in this embodiment of the invention; Figure 9 This is a graph showing the S11 parameters, gain, and axial ratio of a high-aperture efficiency terahertz antenna provided in an embodiment of the present invention. Figure 10 This is the simulated and tested radiation pattern of the high-aperture efficiency terahertz antenna at 220 GHz in an embodiment of the present invention.

[0019] The reference numerals in the figure are as follows: 1-Metal feed layer; 2-Metal resonant layer; 21-Resonant through-slot; 3-Metasurface structure unit; 31-Dielectric substrate; 32-Second metal layer; 321-Clearing position; 4-Metasurface reflective component; 41-Bottom metal; 411-Bottom gap; 42-Dielectric layer; 43-Top metal; 431-Top gap; 5-Metal ground layer; 51-Ground through-slot; 6-First impedance matching layer; 61-First matching layer gap; 62-Second matching layer gap; 7-Second impedance matching layer; 71-Third matching layer gap; 8-Third impedance matching layer; 81-Fourth matching layer gap; 82-Fifth matching layer gap; 9-Fourth impedance matching layer; 91-Sixth matching layer gap; 92-Seventh matching layer gap; 10-Adapter; 11-Screw; 12-Calibration column. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] In the description of this invention, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use, or the orientation or positional relationship in which those skilled in the art would usually understand. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] The terms "first," "second," etc., used in this invention are merely for descriptive purposes and have no special meaning.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Obviously, the above embodiments are merely examples for clear illustration and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

[0024] Example This embodiment provides a high-aperture-efficiency terahertz antenna, aiming to solve the problem of low aperture utilization caused by high transmission loss in traditional antennas at high frequencies. Please refer to [link to relevant documentation]. Figures 1-8The high-aperture efficiency terahertz antenna provided in this embodiment includes a metal resonant cavity unit, which includes a metal feed layer 1 and a metal resonant layer 2 stacked sequentially. The metal resonant layer 2 has a resonant through-slot 21. A metasurface structure unit 3 is stacked and connected to the surface of the metal resonant layer 2. The metasurface structure unit 3 specifically includes a first metal layer (not shown in the figure), a dielectric substrate 31, and a second metal layer 32 stacked and connected to the surface of the metal resonant layer 2. The dielectric substrate 31 and the first metal layer and the second metal layer 32 closely attached to both sides of the dielectric substrate 31 form a PCB structure. The dielectric substrate 31 can be a Rogers 5880 dielectric board with a thickness of 0.045λ0-0.064λ0, or a low-loss quartz plate with a thickness of 0.030λ0-0.070λ0. When the dielectric substrate 31 is made of Rogers 5880 material, its thickness is preferably 0.055λ0; when the dielectric substrate 31 is made of low-loss quartz material, its thickness is preferably 0.05λ0. In this embodiment, λ0 refers to the wavelength at the antenna operating frequency, which is 220GHz. The first metal layer and the second metal layer 32 are copper layers, which can be protected against oxidation using an immersion gold process to improve the antenna's lifespan and operational stability. A cutout 321 is formed in the center of the second metal layer 32, and an M-row, N-column metasurface reflective component 4 is disposed within the cutout 321. Specifically, M is 5-7 and N is 5-7.

[0025] The high-aperture-efficiency terahertz antenna provided in this embodiment is based on a metal feed layer and a metasurface structure unit with a dielectric substrate. The linearly polarized signal wave output by the metal feed layer is reflected multiple times in the metal resonant cavity, achieving high aperture efficiency in the terahertz band. The transmitting component structure of the metasurface structure unit achieves high gain. The terahertz antenna has stable beam performance, a simple and highly integrated antenna structure, and a small size. It also has high circular polarization conversion efficiency, which can meet the needs of long-distance communication.

[0026] Furthermore, a metal ground layer 5 is provided between the metal feed layer 1 and the metal resonant layer 2. The metal ground layer 5 has a ground slot 51, which is connected to the resonant slot 21. At least one metal impedance matching layer is also provided between the metal feed layer 1 and the metal ground layer 5. The metal impedance matching layer has a matching layer slot structure. The metal impedance matching layer overcomes the impedance mismatch problem caused by the high reflectivity of the metasurface structure unit, optimizes the impedance matching near the operating frequency, and enables the antenna to operate within the required operating frequency band.

[0027] In this embodiment, preferably, the metal impedance matching layer includes: a first impedance matching layer 6, a second impedance matching layer 7, a third impedance matching layer 8, and a fourth impedance matching layer 9 disposed between the metal ground layer 5 and the metal feed layer 1 and stacked sequentially in a direction away from the metal ground layer 5.

[0028] The metal feed layer 1, metal impedance matching layer, metal ground layer 5, and metal resonant layer 2 are all made of copper, and in this embodiment, copper is preferred. The copper sheet is CNC machined to obtain the material. To facilitate processing and assembly and improve assembly accuracy, in this embodiment, the metal resonant layer 2, metal ground layer 5, first impedance matching layer 6, and second impedance matching layer 7 are made as one unit, the third impedance matching layer 8 and fourth impedance matching layer 9 are made as one unit, and the metal feed layer 1 is made as a separate unit. After stacking and assembling the three units, they are assembled together with the metasurface structure unit 3 to form a high-aperture efficiency terahertz antenna. This operation results in smaller assembly errors and higher antenna accuracy.

[0029] Specifically, such as Figures 1-2 As shown, the metal resonant layer 2 is a cuboid plate structure with a length and width of 3λ0-10λ0. In this embodiment, preferably, the length and width of the metal resonant layer 2 are both 6.5λ0, and the thickness is 0.41λ0-0.51λ0, preferably 0.46λ0 in this embodiment. A resonant through slot 21 with a length and width of 2.15λ0-2.25λ0 is formed in the center of the metal resonant layer 2. In this embodiment, preferably, the length and width of the resonant through slot 21 are both 2.2λ0, that is, the resonant through slot 21 is a square slot, which serves as the main resonant space of the antenna. The metal feed layer 1 is also a cuboid plate structure with the same length and width as the metal resonant layer 2, and a thickness of 0.3λ0-1λ0, preferably 0.6λ0 in this embodiment. The metal feed layer 1 is a waveguide layer that serves to connect to the radio frequency system. It has a connection interface for connecting to a signal source. The metal feed layer 1 is connected to an adapter 10, which is a WR-4 waveguide flange. The waveguide input port of the WR-4 waveguide flange is connected to the connection interface. The WR-4 waveguide flange is used to reduce leakage when the antenna is connected to the radio frequency system. At the same time, the flange also serves to connect to the external radio frequency system.

[0030] The metal ground layer 5 is a cuboid plate structure, with the same length and width as the metal resonant layer 2, and a thickness of 0.06λ0-0.08λ0, preferably 0.07λ0 in this embodiment. A trapezoidal platform-shaped ground channel 51 is provided in the center of the metal ground layer 5. The ground channel 51 is adapted to and connected with the resonant channel 21. The length and width of the ground channel 51 are the same as those of the resonant channel 21. That is, in this embodiment, the upper bottom of the ground channel 51 is the resonant channel 21, and its length and width are preferably 2.2λ0. The lower bottom of the ground channel 51 has a length of 0.95λ0-1.05λ0 and a width of 0.75λ0-0.85λ0. In this embodiment, preferably, the lower bottom of the ground channel 51 is a rectangular channel with a length of 1.0λ0 and a width of 0.8λ0. The hollow trapezoidal platform-shaped channel can achieve the effect of beam concentration, which can provide the antenna with a converged beam with higher aperture efficiency, thereby improving the antenna gain.

[0031] Each impedance matching layer is also a cuboid plate structure, with length and width dimensions identical to those of the metal resonant layer 2. The total thickness of the metal impedance matching layer is 0.95λ0-1.05λ0, preferably 1λ0 in this embodiment. Figure 5As shown, the first impedance matching layer 6 has a first matching layer gap 61 and a second matching layer gap 62 spaced apart in the center. The lengths of the first matching layer gaps 61 and 62 are both 0.83λ0-0.93λ0, preferably 0.88λ0 in this embodiment, and the widths are 0.41λ0-0.51λ0, preferably 0.46λ0 in this embodiment. The first matching layer gap 61 and the second matching layer gap 62 are arranged parallel to each other and are symmetrical about the centerline of the first impedance matching layer 6. The distance between them is 0.1λ0-0.2λ0, preferably 0.15λ0 in this embodiment. The second impedance matching layer 7 has a third matching layer gap 71 in the center. The length of the third matching layer gap 71 is 1.45λ0-1.55λ0 and the width is 1.05λ0-1.15λ0. In this embodiment, the third matching layer gap 71 is preferably a rectangular groove with a length of 1.5λ0 and a width of 1.1λ0. The third impedance matching layer 8 has a fourth matching layer gap 81 and a fifth matching layer gap 82 spaced apart in the center. The length of the fourth matching layer gap 81 and the fifth matching layer gap 82 is 0.45λ0-0.55λ0, preferably 0.5λ0 in this embodiment, and the width is 0.28λ0-0.38λ0, preferably 0.33λ0 in this embodiment. The fourth matching layer gap 81 and the fifth matching layer gap 82 are arranged in parallel and symmetrically with respect to the centerline of the third impedance matching layer 8. The distance between them is 0.02λ0-0.12λ0, preferably 0.07λ0 in this embodiment. The fourth impedance matching layer 9 has a sixth matching layer slot 91 and a seventh matching layer slot 92 spaced apart in its center. The lengths of both slots 91 and 92 are 0.83λ0-0.93λ0 (preferably 0.88λ0 in this embodiment), and their widths are 0.46λ0-0.56λ0 (preferably 0.51λ0 in this embodiment). The slots 91 and 92 are parallel and symmetrical with respect to the centerline of the fourth impedance matching layer 9. The distance between them is 0.13λ0-0.23λ0 (preferably 0.18λ0 in this embodiment). The slots in each impedance matching layer extend in the same direction, and the slots in adjacent impedance matching layers are parallel. The setting of each impedance matching layer and the matching layer gap overcomes the impedance mismatch caused by the high reflectivity surface of the antenna, so that the antenna can operate within the preset operating frequency band. Through the above-mentioned gap structure and size parameter settings, the antenna can achieve the optimal standing wave characteristics at a specific reference frequency, thereby achieving the highest gain radiation at the reference frequency and finally obtaining the optimal aperture efficiency.

[0032] To simplify antenna assembly and improve assembly accuracy, the high-aperture efficiency terahertz antenna provided in this embodiment is assembled in the following manner: after stacking and assembling a unit made of a metal resonant layer 2, a metal ground layer 5, a first impedance matching layer 6, a second impedance matching layer 7, a unit made of a third impedance matching layer 8 and a fourth impedance matching layer 9, and a metal feed layer 1, the metasurface structure unit 3 is assembled on the top surface of the metal resonant layer 2 and fixedly connected by a screw array. That is, the metal feed layer 1, the metal impedance matching layer, the metal ground layer 5, the metal resonant layer 2, and the metasurface structure unit 3 are fixedly connected by a screw array. In the screw array, the distance between each screw 11 and the metasurface structure unit 3 is greater than 1λ0 to prevent the screw 11 from affecting the antenna performance.

[0033] The high-aperture efficiency terahertz antenna provided in this embodiment is also equipped with four calibration posts 12 at the four corners. The calibration posts play a positioning role and realize the effect of improving the assembly accuracy of the metasurface structure unit 3 and the metal resonant cavity unit.

[0034] Please see Figure 1 , Figures 6-8In the metasurface structure unit 3, an M-row N-column metasurface reflective component 4 is arranged within the hollowed-out position 321, where M and N are both 5-7. The outer perimeter length and width of each metasurface reflective component are both 0.3λ0-0.45λ0. In this embodiment, preferably, a 6-row 6-column metasurface reflective component 4 is arranged within the hollowed-out position 321. The outer perimeter dimensions of each metasurface reflective component 4 are: length and width are both 0.36λ0. The center distance between two adjacent metasurface reflective components 4 is 0.3λ0-0.45λ0, preferably 0.4λ0 in this embodiment. The specific structure of each metasurface reflective component 4 is as follows: the metasurface reflective component 4 includes a bottom metal 41, a dielectric layer 42, and a top metal 43 stacked sequentially. The bottom metal 41 is connected to the dielectric substrate 31. The top metal has a top gap 431, and the bottom metal has a bottom gap 411. The dielectric layer 42 is a cuboid plate structure with the same length and width, preferably 0.36λ0 in this embodiment, and a thickness of 0.08λ0-0.12λ0, preferably 0.1λ0 in this embodiment. Specifically, the dielectric layer 42 is a Rogers 5880 dielectric plate with a dielectric constant of 2.2 and a loss of 0.001. As an alternative implementation, the dielectric layer 42 can also be made of quartz material. Both the top metal 43 and the bottom metal 41 are made of 0.5 oz thick gold-plated copper. The cross-sectional shape of the top metal 43 is hexagonal, which is obtained by removing one set of diagonals from a rectangular metal sheet with a length of 0.3λ0 and a width of 0.25λ0 (i.e., removing two opposite isosceles right triangles from the rectangular metal sheet). The lengths of the two right-angled sides of the removed isosceles triangles are 0.05λ0-0.13λ0, preferably 0.1λ0 in this embodiment. The centerline of the top metal 43 coincides with the diagonal of the dielectric layer 42, that is, the top metal 43 is set at a 45° angle in the center of the dielectric layer 42. The top gap 431 is opened in the center of the top metal, and the top gap 431 is a rectangular gap extending along the diagonal of the dielectric layer 42 in the length direction, with a length of 0.15λ0 and a width of 0.056λ0. It is used to provide linear-to-circular polarization torsion. The bottom metal 41 is a rectangular metal layer, and its length and width are the same as those of the dielectric layer 42. That is, the bottom metal 41 is a square metal layer that covers the bottom surface of the dielectric layer 42. The bottom gap 411 is a rectangular gap opened in the center of the bottom metal 41. The bottom gap 411 is parallel to a pair of opposite sides of the bottom metal 41. The length of the bottom gap 411 is 0.25λ0-0.3λ0 and the width is 0.056λ0.In each metasurface reflector 4, the length of the bottom gap 411 is not exactly the same (set to different lengths according to a preset distribution) so that the antenna aperture field can obtain a more uniform amplitude distribution. By adjusting the length of the bottom gap 411 in different metasurface reflector 4, the reflection coefficient and transmission coefficient of electromagnetic waves after passing through the unit can be adjusted, thus obtaining a higher antenna gain. The length of the bottom gap 411 in the metasurface reflector 4 is calculated by resonant radiation to obtain the reflector with the best reflection resonance effect. Metasurface reflectors with different bottom gap lengths form a non-uniform array surface, and at the same time, they work together with the metal resonant cavity unit. Using the principle of resonant cavity gain excitation, high gain of the terahertz band antenna beam is achieved.

[0035] The working principle of the high-aperture efficiency terahertz antenna provided in this embodiment is as follows: A WR-4 signal source is connected below the metal feed layer 1 to feed the signal into the multilayer coupling layer. By utilizing multiple impedance adjustments of the metal cavity, the input impedance of the signal above the feed is controlled, thereby achieving a standing wave near the 220GHz bandwidth. The inclined ground through-slot 51, the resonant through-slot 21, and the dielectric substrate 31 form a Fabry-Robbin cavity resonant structure. When the signal reaches this resonant cavity, the output signal wave undergoes multiple resonance superpositions here, and finally outputs a high-gain beam after polarization torsion by the metasurface structure unit 3.

[0036] Test case 1. The test results show the S11 parameter curves, gain curves, and axial ratio curves of the high-aperture efficiency terahertz antenna provided in the test embodiment as a function of frequency. Figure 9 As shown.

[0037] As can be seen from the figure, the antenna can meet the conditions of 3dB gain bandwidth and 3dB axial ratio bandwidth in the range of 218-244GHz.

[0038] 2. The radiation pattern of the high-aperture efficiency terahertz antenna provided in the test embodiment is shown in the test results. Figure 10 As shown.

[0039] As can be seen from the E-plane radiation pattern shown in the figure, the antenna has low sidelobe gain and excellent axial ratio purity at the 220 GHz frequency point. At the same time, the results of physical measurement are in good agreement with the simulation results, which can confirm the technical effect of the antenna.

[0040] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-aperture-efficiency terahertz antenna, characterized in that, include: A metal resonant cavity unit includes a metal feed layer and a metal resonant layer stacked sequentially, wherein the metal resonant layer has a resonant through slot; A metasurface structure unit is stacked and connected to the surface of the metal resonant layer. The metasurface structure unit includes a first metal layer, a dielectric substrate, and a second metal layer sequentially connected to the surface of the metal resonant layer. A cutout is formed in the center of the second metal layer, and an M-row N-column metasurface reflective component is arranged in the cutout, where M and N are both 5-7.

2. The high-aperture efficiency terahertz antenna according to claim 1, characterized in that, A metal ground layer is also provided between the metal feed layer and the metal resonant layer. The metal ground layer has a ground channel, which is connected to the resonant channel.

3. The high-aperture efficiency terahertz antenna according to claim 2, characterized in that, At least one metal impedance matching layer is provided between the metal feed layer and the metal ground layer, and the metal impedance matching layer has a matching layer gap structure.

4. The high-aperture efficiency terahertz antenna according to any one of claims 1-3, characterized in that, The metasurface reflective assembly includes a bottom metal layer, a dielectric layer, and a top metal layer stacked sequentially. The bottom metal layer is connected to the dielectric substrate. The top metal layer has a top gap, and the bottom metal layer has a bottom gap. The length and width of the outer periphery of the metasurface reflective assembly are both 0.3λ0-0.45λ0, and the center-to-center distance between adjacent metasurface reflective assemblies is 0.3λ0-0.45λ0, where λ0 is the wavelength at the antenna operating frequency.

5. The high-aperture efficiency terahertz antenna according to claim 4, characterized in that, The dielectric layer is a cuboid plate structure with a thickness of 0.08λ0-0.12λ0. The top metal has a hexagonal cross-section and is obtained by removing a set of diagonals from a rectangular metal sheet with a length and width of 0.2λ0-0.35λ0. The top gap is a rectangular gap located in the center of the top metal and extending along the diagonal of the dielectric layer, with a length of 0.1λ0-0.2λ0 and a width of 0.045λ0-0.065λ0. The bottom metal is a rectangular metal layer with the same length and width as the dielectric layer. The bottom gap is a rectangular gap located in the center of the bottom metal, with a length of 0.25λ0-0.3λ0 and a width of 0.045λ0-0.065λ0.

6. The high-aperture efficiency terahertz antenna according to claim 3, characterized in that, The metal resonant layer is a cuboid plate structure with a length and width of 3λ0-10λ0 and a thickness of 0.41λ0-0.51λ0. A resonant through slot with a length and width of 2.15λ0-2.25λ0 is formed in the center of the metal resonant layer. The metal feed layer is a cuboid plate structure with the same length and width as the metal resonant layer and a thickness of 0.3λ0-1λ0, where λ0 is the wavelength at the antenna operating frequency.

7. The high-aperture efficiency terahertz antenna according to claim 6, characterized in that, The metal ground layer is a rectangular plate structure, with its length and width being the same as those of the metal resonant layer, and its thickness being 0.06λ0-0.08λ0. A trapezoidal platform-shaped ground channel is formed in the center of the metal ground layer. The upper base length and width of the ground channel are the same as those of the resonant channel, and the lower base length is 0.95λ0-1.05λ0 and the width is 0.75λ0-0.85λ0.

8. The high-aperture efficiency terahertz antenna according to claim 7, characterized in that, The metal impedance matching layer includes a first impedance matching layer, a second impedance matching layer, a third impedance matching layer and a fourth impedance matching layer stacked sequentially in a direction away from the metal ground layer. The length and width of the metal impedance matching layer are the same as the length and width of the metal resonant layer, respectively, and the thickness is 0.95λ0-1.05λ0.

9. The high-aperture efficiency terahertz antenna according to claim 8, characterized in that, The first impedance matching layer has a first matching layer gap and a second matching layer gap spaced apart at its center. The length of the first matching layer gap and the second matching layer gap are 0.83λ0-0.93λ0, and the width is 0.41λ0-0.51λ0. The distance between the first matching layer gap and the second matching layer gap is 0.1λ0-0.2λ0. The second impedance matching layer has a third matching layer gap spaced apart at its center. The third impedance matching layer has a fourth matching layer gap and a fifth matching layer gap spaced apart at its center. The fourth and fifth matching layer gaps have a length of 0.45λ0-0.55λ0 and a width of 0.28λ0-0.38λ0, and the distance between the fourth and fifth matching layer gaps is 0.02λ0-0.12λ0. A sixth and seventh matching layer gap are spaced apart in the center of the fourth impedance matching layer. The sixth and seventh matching layer gaps have a length of 0.83λ0-0.93λ0 and a width of 0.46λ0-0.56λ0, and the distance between the sixth and seventh matching layer gaps is 0.13λ0-0.23λ0.

10. The high-aperture efficiency terahertz antenna according to claim 9, characterized in that, The metal feed layer, metal impedance matching layer, metal ground layer, metal resonant layer, and metasurface structure unit are fixedly connected by a screw array. In the screw array, the distance between each screw and the metasurface structure unit is greater than 1λ0. The metal feed layer is also connected to an adapter.

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