Holographic metasurface antenna

Abstract

The utility model provides a holographic metasurface antenna. The holographic metasurface antenna is composed of three layers of parallel plates, namely a first parallel plate and a third parallel plate which are made of metal materials and a second parallel plate made of circuit board base materials. Substrate integrated waveguides are evenly distributed on the periphery of the first parallel plate at intervals, the plate face comprises a plurality of grid units, each unit is provided with sub-wave size gaps, and metal patches are embedded between the gaps. And the center of the third parallel plate is provided with a coaxial feed monopole antenna. According to the design, effective coupling and regulation of electromagnetic waves are achieved through the gap of the first parallel plate and the metal patch, the monopole antenna of the third parallel plate serves as a feed source, columnar reference waves are generated to be coupled with the metasurface gap unit, and then the gain of the holographic metasurface antenna is improved. The overall structure is compact and functions are efficient.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of antennas, and particularly relates to a holographic metasurface antenna. BACKGROUND

[0002] With the continuous development of holographic antenna technology and the wide application of electromagnetic super materials with high impedance characteristics, the combination of impedance modulation theory and optical holographic principle brings new breakthroughs to antenna design. As a new type of antenna form, the holographic metasurface antenna can effectively manipulate electromagnetic waves through impedance modulation, thereby generating beams with specific polarization characteristics and directivity.

[0003] In the design of traditional reflective or transmissive metasurface array antennas, the required phase distribution at each position in the array surface needs to be accurately calculated according to the position of the feed source, and the position of the feed source is closely related to the size of the array antenna aperture. When the metasurface array aperture increases, the feed source needs to be further away from the metasurface array, which will lead to an increase in the antenna profile, which is not conducive to the miniaturization and low profile design of the antenna.

[0004] In order to solve the above problems, researchers have begun to explore new antenna design methods. Among them, constructing a holographic metasurface antenna capable of generating linearly polarized beams through the principle of polarized particles has become a feasible scheme. However, the existing holographic metasurface antennas designed based on the principle of polarized particles have the problem of low gain, which limits their performance in practical applications. CONTENT OF THE INVENTION

[0005] The purpose of the present application is to overcome the defects in the prior art and provide a holographic metasurface antenna.

[0006] The present application provides a holographic metasurface antenna, comprising: a first parallel plate, a second parallel plate and a third parallel plate.

[0007] The first parallel plate, the second parallel plate and the third parallel plate are three layers stacked in sequence, the first parallel plate and the third parallel plate are of metal material, and the second parallel plate is of circuit board base material.

[0008] The first parallel plate is provided with uniformly spaced substrate integrated waveguides around the periphery, and a plurality of grid elements are arranged on the plate surface, each grid element is provided with a gap, a metal patch is arranged between the gaps, and the gap size is set to a sub-wavelength structure.

[0009] The third parallel plate is provided with a monopole antenna at the center position of the coaxial feed.

[0010] Optionally, the grid elements are arranged in a 21x21 array.

[0011] Optionally, the monopole antenna of the coaxial feed serves as an excitation source to generate a cylindrical reference wave for coupling the metasurface slots 101.

[0012] Optionally, the cylindrical reference wave is described using a zero-order Hankel function of the first kind.

[0013] Optionally, the slots include a rectangular slot along the x-axis direction and a rectangular slot along the y-axis direction.

[0014] The rectangular slot along the x-axis direction is coupled with the x-component of the reference wave magnetic field to generate a y-polarized wave.

[0015] The rectangular slot along the y-axis direction is coupled with the y-component of the reference wave magnetic field to generate an x-polarized wave.

[0016] The beneficial effects of the present application are:

[0017] The present application provides a holographic metasurface antenna, comprising: a first parallel plate, a second parallel plate and a third parallel plate; the first parallel plate, the second parallel plate and the third parallel plate are three layers in turn, the first parallel plate and the third parallel plate are metal materials, and the second parallel plate is a circuit board substrate material; the first parallel plate is provided with uniformly spaced substrate integrated waveguides around the periphery, and a plurality of grid units are arranged on the plate surface, a slot is arranged at the position of each grid unit, a metal patch is arranged between the slots, and the size of the slot is set as a sub-wavelength structure; a monopole antenna of a coaxial feed is arranged at the center position of the third parallel plate. The present application realizes effective coupling and regulation of electromagnetic waves by arranging a slot at the position of the grid unit on the first parallel plate and adding a metal patch between the slots; a monopole antenna of a coaxial feed is arranged at the center position of the third parallel plate, which serves as an excitation source to generate a cylindrical reference wave for coupling the metasurface slot units, thereby improving the gain of the holographic metasurface antenna. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of a holographic metasurface antenna in the present application;

[0019] Figure 2 is a schematic diagram of the phase distribution of the Hy component reference wave in the present application;

[0020] Figure 3 is a schematic diagram of the slot distribution in the present application;

[0021] Figure 4 is a schematic diagram of the reflection coefficient in the present application;

[0022] Figure 5 is a schematic diagram of the gain before and after adding the substrate integrated waveguide in the present application. DETAILED DESCRIPTION

[0023] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, the described embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0024] Referring to Figure 1 The present application provides a holographic metasurface antenna.

[0025] First, a linearly polarized holographic metasurface antenna working at 24 GHz is created.

[0026] Second, a substrate integrated waveguide 103 is added around the metasurface to reduce the leakage of reference wave energy and thus increase the gain.

[0027] The linearly polarized holographic metasurface antenna includes a three-layer parallel plate waveguide structure, including a first parallel plate, a second parallel plate, and a third parallel plate stacked in order.

[0028] The first parallel plate and the third parallel plate are made of metal, in particular, copper.

[0029] The second parallel plate uses a dielectric substrate of Rogers 3003 board material with a dielectric constant εr = 3, a loss tangent tan δ = 0.001, and a height h1 = 1.5 mm.

[0030] The first parallel plate is discretized into a unit network, and each grid position is slotted and a metal patch 102 is added in the slot 101 to couple the electromagnetic wave emitted by the center feed source, wherein each slot 101 unit is a subwavelength size structure.

[0031] The third parallel plate is inserted with a monopole antenna of a coaxial feed as an excitation.

[0032] In order to reduce the size of the antenna and reduce the profile, a monopole antenna built-in the center of the holographic metasurface antenna is used as a feed source to generate a cylindrical reference wave for coupling the slot 101 unit of the metasurface, and the zero-order first Hankel function is used to describe:

[0033]

[0034] where k g represents the wave number in the dielectric substrate, r is the distance from the discrete aperture position on the first parallel plate to the center origin coordinate position. ψ represents the azimuth angle of each point on the metasurface antenna.

[0035] As Figure 2As shown, the phase distribution of the reference wave on the two components (21x21 unit) of the holographic metasurface antenna can be calculated. The rectangular slot 101 along the x-axis direction can be coupled with the x component of the reference wave magnetic field to generate a y polarized wave. Similarly, the rectangular slot 101 along the y-axis direction can be coupled with the y component of the reference wave magnetic field to make the radiation generate an x polarized wave.

[0036] Before designing the holographic interference plane, the target radiation field with the desired polarization and direction is determined. The linearly polarized wave beam to be generated is regarded as the target wave P obj , which is radiated vertically along the normal direction of the metasurface. At the same time, the holographic metasurface interference plane can be represented as follows:

[0037]

[0038] wherein is the complex conjugate of the reference magnetic field, and M represents the interference field containing the reference field and the target field, that is, the hologram on the metasurface. According to the formula, the distribution state of the metasurface surface unit can be calculated, as shown in Figure 3 .

[0039] As shown in Figure 4 , in order to verify the working condition of the proposed linearly polarized holographic metasurface antenna at f = 24 GHz, the antenna is simulated and tested in HFSS. The range of the super surface antenna reflection coefficient (S11) less than -10 dB without adding the substrate integrated waveguide 103 is from 23.85 GHz to 24.3 GHz; the range of the super surface antenna reflection coefficient less than -10 dB with adding the substrate integrated waveguide 103 is from 23.75 GHz to 24.05 GHz, which has good impedance matching.

[0040] As shown in Figure 5 , the maximum gain of the antenna before and after adding the substrate integrated waveguide 103 increases from 13.30 dBi to 15.42 dBi, and the gain of the antenna under the same condition increases by 2.12 dB after adding the substrate integrated waveguide 103. This proves that the gain of the metasurface antenna can be improved after adding the substrate integrated waveguide 103.

[0041] The above description of the embodiments of the present application cannot be understood as a limitation of the present application, and those skilled in the art can modify, replace and change the above embodiments within the scope of the application.

Claims

1. A holographic metasurface antenna, characterized in that, The utility model relates to a kind of metasurface antenna, including: First parallel plate, second parallel plate and third parallel plate; The first parallel plate, second parallel plate and third parallel plate are three layers in turn, the first parallel plate and the third parallel plate are metal material, and the second parallel plate is circuit board base material material; The first parallel plate is provided with evenly spaced substrate integrated waveguide around, and a plurality of grid units are arranged on the board surface, the position of each grid unit is provided with slit, and metal patch is arranged between the slit, and the slit size is set to sub-wave size structure; The third parallel plate center position is provided with coaxial feed's monopole antenna.

2. The holographic metasurface antenna of claim 1, wherein, The grid unit is 21×21 array distribution.

3. The holographic metasurface antenna of claim 1, wherein, Coaxial feed's monopole antenna is used as excitation source, and columnar reference wave for coupling metasurface slit is generated.

4. The holographic metasurface antenna of claim 3, wherein, The columnar reference wave is described using zero-order first Hankel function.

5. The holographic metasurface antenna of claim 1, wherein, The slit includes rectangular slit along x-axis direction and rectangular slit along y-axis direction; Rectangular slit along x-axis direction is coupled with the x component of reference wave magnetic field to generate a y polarized wave; Rectangular slit along y-axis direction is coupled with the y component of reference wave magnetic field to generate an x polarized wave.

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