A low-profile, broadband, high-gain, and high-aperture-efficiency metasurface antenna

Abstract

The present invention discloses a low-profile, broadband, high-gain, and high-aperture efficiency metasurface antenna, which belongs to the field of antenna technology. It includes, from top to bottom, a metasurface structure layer, a first dielectric loading layer, a radiation patch layer, a second dielectric loading layer, a drive patch layer, and a feed layer. The metasurface structure is composed of metasurface units arranged at a specific spacing, and the overall structure of the antenna is processed by a multi-layer printed circuit board process, and finally output by a labeled SSMP RF connector. The antenna adopts a metasurface loading and microstrip line back-feed structure, so that the antenna obtains good directivity and high gain. At the same time, by using dielectric loading instead of the traditional air loading layer, the design and processing difficulty of the metasurface antenna is greatly simplified. The present invention greatly reduces the difficulty of assembling and welding the antenna unit in the later stage, and also increases the reliability of the antenna. The present invention has the advantages of simple structure, high gain, low profile, and low difficulty in processing, assembling, and welding.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a low-profile, broadband, high-gain, and high-aperture efficiency metasurface antenna. Background Art

[0002] Aerospace wireless system equipment requires high-quality and high-reliability communication links, which are not only used to achieve safe flight and rapid emergency response, but also to provide timely and accurate radar signals for navigation and guidance subsystems. To achieve the above requirements, high-gain airborne antennas are key components. On the other hand, in order to obtain a larger system communication capacity, the antenna is usually required to have broadband working characteristics, and the antenna should also meet the characteristics of light weight, small size, easy conformality, and low profile of the airborne. Generally speaking, there is an unavoidable contradiction between the bandwidth and gain of the antenna and the physical size of the antenna. In order to obtain high gain over a wide bandwidth, it is usually necessary to relax the size of the antenna. On the contrary, if you want to make the radiation structure more compact, you often need to make certain sacrifices in bandwidth and gain. By using a new metasurface structure and low-profile low-Q value loading technology, it is possible to achieve high-gain directional radiation of the antenna in a wide bandwidth while ensuring that the antenna has a low profile and compact size, and at the same time achieve a higher aperture efficiency. It also has the advantages of low profile and easy integration, and has great application prospects in airborne, satellite-borne, missile-borne and other antenna applications. Therefore, in order to achieve high-gain antenna design with low profile and high bandwidth requirements, it is necessary to conduct research on new metasurface-loaded microstrip patch antennas.

[0003] Due to the variety of metamaterials and their wide range of applications, metamaterials have been widely used in antenna miniaturization, electromagnetic wavefront control, high-efficiency transmission and reflection array antennas. Among them, printed metasurface structures not only have flexible and changeable design methods, but can also be formed using common PCB technology, while ensuring good processing accuracy and achieving low production costs. Therefore, they are being widely studied by scholars at home and abroad.

[0004] There are two main types of metasurface-based antenna designs. The first is to use the metasurface as a reflector for the omnidirectional radiating antenna unit. Compared with metal reflectors (mostly backplanes or back cavities), metasurface reflectors can achieve directional radiation of the antenna while ensuring the overall low profile of the antenna. The second is to use the metasurface as the transmission layer of the antenna. By loading a periodic metasurface structure above the antenna radiating unit, the port characteristics and radiation gain of the antenna can be improved. The advantages of the metasurface are numerous, but the disadvantages are also obvious. A certain air layer is required between the metasurface and the antenna radiating unit to reduce the Q value in order to achieve broadband impedance matching. This will cause various processing and assembly problems in the actual engineering process. For example, at higher frequencies, the loading distance between the antenna and the metasurface is difficult to accurately modulate, and there are problems with the antenna's feeding structure and RF connector welding. Summary of the invention

[0005] In view of this, the present invention provides a low-profile, broadband, high-gain, and high-aperture efficiency metasurface antenna. The antenna reduces the later manual assembly process, greatly reduces the difficulty of assembling the metasurface antenna, especially in the high-frequency band; and has the advantages of excellent electrical performance, high degree of integration, low profile, simple structure, convenient processing, and low cost.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A low-profile, broadband, high-gain, and high-aperture efficiency metasurface antenna, comprising a metasurface structure layer, a first dielectric loading layer, a radiation patch layer, a second dielectric loading layer, a driving patch layer, and a feeding layer stacked in sequence from top to bottom;

[0008] The super surface structure layer comprises a first dielectric plate, and a super surface structure is printed on the upper surface of the first dielectric plate;

[0009] The first dielectric loading layer includes a second dielectric plate, and the second dielectric plate is provided with two upper hollow structures, and the upper hollow structures are located directly above the corresponding radiation patches;

[0010] The radiation patch layer includes a third dielectric plate, and two parallel radiation patches are arranged on the upper surface of the third dielectric plate;

[0011] The second dielectric loading layer includes a fourth dielectric plate, and two lower hollow structures are provided on the fourth dielectric plate, and the lower hollow structures are located directly below the corresponding radiation patches;

[0012] The driving patch layer includes a fifth dielectric plate, and two parallel driving patches are printed on the upper surface of the fifth dielectric plate, and the driving patches are located directly below the corresponding radiation patches;

[0013] The feeding layer includes a sixth dielectric plate; a metal floor is provided on the upper surface of the sixth dielectric plate, and a feeding network is provided on the lower surface of the sixth dielectric plate; the feeding network includes a T-junction power divider and a microstrip feeder, wherein the input end of the T-junction power divider is connected to the output end of the microstrip feeder, and is used to divide the power of the input end microstrip line equally; metal probes are provided at the ends of the two branches of the T-junction power divider, and one end of the top of the metal probe passes through the sixth dielectric plate, the metal floor and the fifth dielectric plate and is connected to the driving patch corresponding to the upper surface of the fifth dielectric plate.

[0014] Furthermore, the metal floor has no contact with the metal probe.

[0015] The beneficial effects of the above technical solution of the present invention are:

[0016] The present invention adopts a metasurface loading and microstrip line back-feed structure, so that the antenna has good directivity and high gain. At the same time, by using dielectric loading instead of the traditional air loading layer, the design and processing difficulty of the metasurface antenna are greatly simplified. At the same time, the multi-layer printed circuit board processing technology is adopted, which greatly reduces the difficulty of assembling and welding the antenna unit (array) in the later stage, and also increases the reliability of the antenna. The metasurface antenna has the advantages of simple structure, high gain, low profile, and low difficulty in processing, assembling and welding. . BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic cross-sectional view of a structure of an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of a feeding structure according to an embodiment of the present invention;

[0019] Figure 3 is a schematic structural diagram of an embodiment of the present invention;

[0020] Figure 4 is S of the embodiment of the present invention 11 (Port reflection coefficient) curve;

[0021] Figure 5 : are active standing wave ratio and real gain curves of an embodiment of the present invention;

[0022] Figure 6 : are the radiation patterns of the H-plane and the E-plane of the embodiment of the present invention at low frequency;

[0023] Figure 7 : are the radiation patterns of the H plane and the E plane of the embodiment of the present invention at the intermediate frequency;

[0024] Figure 8 It is the radiation pattern of the H plane and the E plane of the embodiment of the present invention at high frequency.

[0025] In the figure: 1. metasurface structure; 2. radiation patch; 3. driving patch; 4. metal floor; 5. metal probe; 6. feeding network; 7. first dielectric plate; 8. second dielectric plate; 9. third dielectric plate; 10. fourth dielectric plate; 11. fifth dielectric plate; 12. sixth dielectric plate. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] A low-profile, broadband, high-gain, and high-aperture efficiency metasurface antenna, comprising a metasurface structure layer, a first dielectric loading layer, a radiation patch layer, a second dielectric loading layer, a driving patch layer, and a feeding layer stacked in sequence from top to bottom;

[0029] The super surface structure layer comprises a first dielectric plate 7, the upper surface of which is printed with a super surface structure 1;

[0030] The first dielectric loading layer includes a second dielectric plate 8, on which two upper hollow structures are provided, and the upper hollow structures are located directly above the corresponding radiation patches 2;

[0031] The radiation patch layer includes a third dielectric plate 9, and two parallel radiation patches are arranged on the upper surface of the third dielectric plate;

[0032] The second dielectric loading layer includes a fourth dielectric plate 10, on which two lower hollow structures are provided, and the lower hollow structures are located directly below the corresponding radiation patches;

[0033] The driving patch layer includes a fifth dielectric plate 11, and two parallel driving patches 3 are printed on the upper surface of the fifth dielectric plate. The driving patch 3 is located directly below the corresponding radiation patch;

[0034] The feeding layer includes a sixth dielectric plate; a metal floor is provided on the upper surface of the sixth dielectric plate 12, and a feeding network 6 is provided on the lower surface of the sixth dielectric plate; the feeding network includes a T-junction power divider and a microstrip feeder, wherein the input end of the T-junction power divider is connected to the output end of the microstrip feeder, so as to divide the power of the input microstrip line equally; metal probes are provided at the ends of the two branches of the T-junction power divider, and one end of the top of the metal probe 5 passes through the sixth dielectric plate, the metal floor 4 and the fifth dielectric plate and is connected to the driving patch corresponding to the upper surface of the fifth dielectric plate.

[0035] Furthermore, the metal floor has no contact with the metal probe.

[0036] The following is a more specific embodiment:

[0037] Figure 1 The figure shows a cross-sectional schematic diagram of a broadband low-profile super-surface antenna structure described in the present invention, which includes a super-surface structure layer, a first dielectric loading layer, a radiation patch layer, a second dielectric loading layer, a driving patch layer, and a feeding layer from top to bottom. The thickness of each layer is designed according to the working frequency band of the antenna. In this embodiment, the antenna working frequency band is the Ku band, and the dielectric plate material used for the super-surface structure layer, the driving patch layer, and the radiation patch layer is Rogers4350B. The thickness of the super-surface structure layer is 0.254mm, the thickness of the radiation patch layer is 0.254mm, and the thickness of the driving patch layer is 0.338mm. The material of the dielectric loading layer is TSM-DS3M, the thickness of the upper dielectric loading layer is 0.508mm, and the thickness of the lower dielectric loading layer is 0.787mm. The material of the feeding layer is TSM-DS3M, and the thickness is 0.254mm. Each layer is pressed together into a whole, and the thickness of the 5 layers of semi-cured sheets is 0.12mm.

[0038] The metasurface is a 4×4 square ring periodic structure, each square ring has an outer side length of 1.66mm, an inner side length of 0.96mm, and a square ring spacing of 1.52mm. Printed on a dielectric board using PCB technology, when the antenna is working, the radiation current can be evenly distributed on the metasurface radiation aperture to achieve high gain.

[0039] The dielectric loading layer consists of two layers, the dielectric is TSM-DS3M, the thickness of the upper dielectric loading layer is 0.508mm, and the thickness of the lower dielectric loading layer is 0.787mm. Each dielectric loading layer has a 10mm×10mm square hole at the position of the microstrip patch to reduce the equivalent dielectric constant and achieve low-profile and low-Q value loading.

[0040] The radiation patch is printed on a 0.254mm thick dielectric board, the board is Rogers4350B, and the dielectric constant is 3.48. The size of the radiation patch is 6.47mm×6.47mm, which can achieve resonant radiation at low frequencies to widen the bandwidth.

[0041] The driver patch is printed on a 0.338mm thick dielectric board, the board material is Rogers4350B, and the dielectric constant is 3.48. The driver patch size is 6.1mm×6.1mm, and the resonant frequency is slightly higher than the radiation patch. A metal probe is used to feed the driver patch, and the input impedance of the feeding point is 25Ohm.

[0042] like Figure 2The figure shows the schematic diagram of the antenna feeding structure of this embodiment. The dielectric substrate is 0.254mm thick, and a metal floor is provided on the upper surface. A circular hole is dug on the metal floor to prevent the metal probe from short-circuiting. A microstrip feed line is provided on the lower surface, with an input impedance of 50Ohm and an output impedance of 25Ohm. A metal probe is used to feed the upper patch. A T-junction power divider is used to equally divide the power of the input microstrip line, which is simple in size and reduces the insertion loss of the overall circuit.

[0043] like Figure 3 The structure of this embodiment is shown, in which the antenna is formed by laminating 6 layers of dielectric plates, and 5 layers of prepreg are added as adhesion, and the thickness of each layer of prepreg is 0.12mm.

[0044] Figure 4 The present invention is a broadband low-profile metasurface antenna structure S 11 (Port reflection coefficient) curve, it can be seen that the antenna has broadband impedance matching characteristics.

[0045] Figure 5 The active standing wave ratio and real gain curves of a broadband low-profile metasurface antenna structure described in the present invention show that the antenna has high gain within the working frequency band, and the average gain within the band is greater than 10dBi.

[0046] Figure 6 It is the radiation pattern of the H plane and E plane of a broadband low-profile metasurface antenna structure at low frequency described in the present invention. The antenna has directional radiation characteristics and a front-to-back ratio greater than 15dB.

[0047] Figure 7 The invention discloses a broadband low-profile metasurface antenna structure having H-plane and E-plane radiation patterns at intermediate frequencies. The antenna has directional radiation characteristics and a front-to-back ratio greater than 15 dB.

[0048] Figure 8 The invention discloses a broadband low-profile metasurface antenna structure having H-plane and E-plane radiation patterns at high frequencies. The antenna has directional radiation characteristics, and a front-to-back ratio greater than 15 dB.

Claims

1. A low-profile, broadband, high-gain, high-aperture efficiency metasurface antenna, characterized in that: It includes a metasurface structure layer, a first dielectric loading layer, a radiation patch layer, a second dielectric loading layer, a driving patch layer and a feeding layer stacked in sequence from top to bottom; The super surface structure layer includes a first dielectric plate, and the upper surface of the first dielectric plate is printed with a super surface structure; the super surface structure is a 4×4 square ring periodic structure The first dielectric loading layer includes a second dielectric plate, and the second dielectric plate is provided with two upper hollow structures, and the upper hollow structures are located directly above the corresponding radiation patches; The radiation patch layer includes a third dielectric plate, and two parallel radiation patches are arranged on the upper surface of the third dielectric plate; the upper hollow structure corresponds to the radiation patches one by one; The second dielectric loading layer includes a fourth dielectric plate, and the fourth dielectric plate is provided with two lower hollow structures, and the lower hollow structures correspond to the radiation patches one by one; the lower hollow structures are located directly below the corresponding radiation patches; The driving patch layer includes a fifth dielectric plate, and two parallel driving patches are printed on the upper surface of the fifth dielectric plate, and the driving patches correspond to the radiation patches one by one; the driving patches are located directly below the corresponding radiation patches; The feeding layer includes a sixth dielectric plate; a metal floor is provided on the upper surface of the sixth dielectric plate, and a feeding network is provided on the lower surface of the sixth dielectric plate; the feeding network includes a T-junction power divider and a microstrip feeder, wherein the input end of the T-junction power divider is connected to the output end of the microstrip feeder, and is used to divide the power of the input end microstrip line equally; metal probes are provided at the ends of the two branches of the T-junction power divider, and one end of the top of the metal probe passes through the sixth dielectric plate, the metal floor and the fifth dielectric plate and is connected to the driving patch corresponding to the upper surface of the fifth dielectric plate.

2. According to claim 1, a low-profile, broadband, high-gain, high-aperture efficiency metasurface antenna, characterized in that: The metal floor has no contact with the metal probe.

Images