阅读说明：本技术 一种双频极化转化超表面单元 (Dual-frequency polarization conversion super-surface unit ) 是由 陈磊 于 2020-05-03 设计创作，主要内容包括：本发明公开了一种双频极化转化超表面单元,包括依次设置的表层金属结构层、中间介质板层和底层金属；表层金属结构层包括第一L型金属贴片、第二L型金属贴片和第一重叠方形金属贴片,整个表层金属结构层为中心对称图形。本发明采用了由两个正方形重叠放置而组成的重叠方形金属贴片和两个L型金属贴片所构成的金属结构,基本单元在8.86GHz附近以及14.98GHz至16.09GHz范围内,能够实现高效的极化转化功能。在线极化电磁波的照射下,单元在上述两个频率范围内能将入射波大部分能量反射至其交叉极化方向,并且入射波同极化方向的反射幅度均小于-10dB。(The invention discloses a dual-frequency polarization conversion super-surface unit, which comprises a surface metal structure layer, a middle medium plate layer and a bottom metal layer which are sequentially arranged, wherein the surface metal structure layer comprises a first L type metal patch, a second L type metal patch and a first overlapped square metal patch, and the whole surface metal structure layer is a centrosymmetric pattern.)

1. A dual-frequency polarization conversion super-surface unit is characterized in that a basic unit comprises a surface metal structure layer (1), a middle medium plate layer (2) and a bottom metal layer (3) which are sequentially arranged from top to bottom, wherein the surface metal structure layer (1) comprises a first L type metal patch (11), a second L type metal patch (12) and a first overlapped square metal patch (13) which are attached to the upper surface of the upper medium plate layer (2), and the whole surface metal structure layer (1) is in a central symmetrical pattern.

2. The unit cell of claim 1, wherein the periodic side length p of the unit cell is 9-11mm, the side lengths L1 of the first L-type metal patch (11) and the second L-type metal patch (12) are 4-5mm, the widths W1 are 0.65-0.85mm, the side lengths L2 of the two overlapping squares of the first overlapping square metal patch (13) are 1-3mm, the distances W2 of the up-down translation and the left-right translation of the two overlapping squares are 1.4-1.6mm, the thickness H of the middle dielectric plate layer (2) is 0.8-1.0mm, the dielectric constant is 4.1-1.5, and the loss tangent is 0.000-0.006.

3. The basic unit of claim 1, wherein the periodic side p of the basic unit is 10mm, the sides L1 of the first L-type metal patch (11) and the second L-type metal patch (12) are both 5mm, the width W1 is 0.75mm, the sides L2 of two overlapped squares of the first overlapped square metal patch (13) are both 2mm, the distances W2 of the two overlapped squares in translation up and down and left and right are both 1.5mm, and the thickness H of the middle dielectric plate layer (2) is 0.9 mm.

4. The base unit of claims 1-3, wherein: under the irradiation of the linear polarization electromagnetic wave, the reflection amplitudes of incident waves in the same polarization direction near 8.86GHz and in the range from 14.98GHz to 16.09GHz are all less than-10 dB, and most energy of the incident waves is reflected to the cross polarization direction of the incident waves.

Technical Field

The invention belongs to the technical field of novel artificial electromagnetic materials, and particularly relates to a super-surface unit with dual-frequency polarization conversion in a microwave band.

Background

The metamaterial is a novel artificial electromagnetic material formed by arranging sub-wavelength unit structures in a periodic or non-periodic mode, and has electromagnetic properties exceeding those of common natural materials. The unusual electromagnetic characteristics of the structure mainly depend on the geometric figure and the size of the sub-wavelength resonance structure. At present, the metamaterial is widely applied to the fields of wave-absorbing materials, electromagnetic stealth, lenses and the like. The super surface, i.e. the two-dimensional metamaterial, has compact structure and flexible processing, and simultaneously maintains unique electromagnetic characteristics, so the super surface gradually starts to replace the original three-dimensional structure. In recent years, various applications are proposed based on the super surface, and various regulation capabilities such as holographic imaging, wave vector regulation, polarization transformation and the like are covered.

Polarization is the law of the variation of the electric field strength vector at a point in space with time. The polarization of electromagnetic waves is important for fundamental physical quantities such as amplitude and phase, and can also be used to transmit information. In the microwave frequency band, the polarization control of electromagnetic waves has wide application in the fields of radar, optical fiber communication, polarization measurement, medical imaging and the like. For example, in object recognition, stealth objects can be identified using polarization properties; in secure communication, it is necessary to change the polarization state of electromagnetic waves in real time.

In recent years, due to rapid development of wireless communication, higher demands have been made on wireless devices, in which dual bands have received more and more attention.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a dual-frequency polarization conversion super-surface unit which can efficiently realize conversion from linear polarization to cross polarization in two frequency ranges.

In order to achieve the purpose, the invention adopts the following technical scheme:

a dual-frequency polarization conversion super-surface unit is characterized in that a basic unit comprises a surface metal structure layer, a middle medium plate layer and bottom metal, wherein the surface metal structure layer, the middle medium plate layer and the bottom metal are sequentially arranged from top to bottom, the surface metal structure layer comprises a first L type metal patch, a second L type metal patch and a first overlapped square metal patch, the first L type metal patch, the second L type metal patch and the first overlapped square metal patch are attached to the upper surface of the upper medium plate layer, and the whole surface metal structure layer.

Furthermore, the periodic side length p of the basic unit is 9-11mm, the side lengths L1 of the first L type metal patch and the second L type metal patch are 4-5mm, the width W1 of the first L type metal patch and the second L type metal patch is 0.65-0.85mm, the side lengths L2 of two overlapped squares of the first overlapped square metal patch are 1-3mm, the vertical translation distance W2 and the horizontal translation distance W2 of the two overlapped squares are 1.4-1.6mm, the thickness H of the middle medium plate layer is 0.8-1.0mm, the dielectric constant is 4.1-1.5, and the loss tangent is 0.000-0.006.

Preferably, the periodic side length p of the basic unit is 10mm, the side lengths L1 of the first L type metal patch and the second L type metal patch are both 5mm, the width W1 of the first 3578 type metal patch and the second L type metal patch are both 0.75mm, the side lengths L2 of the two overlapped squares of the first overlapped square metal patch and the second overlapped square metal patch are both 2mm, the vertical translation distance W2 and the horizontal translation distance W2 of the two overlapped squares are both 1.5mm, and the thickness H of the middle medium plate layer is 0.9 mm.

Furthermore, under the irradiation of the linear polarized electromagnetic wave, the reflection amplitudes of the super-surface basic unit in the same polarization direction near 8.86GHz and in the range from 14.98GHz to 16.09GHz are both less than-10 dB, and most energy of incident waves is reflected to the cross polarization direction of the incident waves.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention adopts a specific metal structure to realize the dual-frequency polarization conversion function of the super-surface basic unit;

2. the invention has certain broadband characteristic, the super-surface basic unit can realize the function in a certain frequency band,

3. the invention has simple processing and convenient realization, and is easy to prepare and process in a microwave frequency band only by depending on simple metal patterns.

Drawings

FIG. 1 is a schematic front view of a basic unit according to the present invention;

FIG. 2 is a schematic view of the reverse structure of the basic unit of the present invention;

FIG. 3 is a schematic cross-sectional view of the basic unit of the present invention;

the metal structure layer comprises 1-a surface metal structure layer, 11-a first L type metal patch, 12-a second L type metal patch, 13-a first overlapped square metal patch, 2-a middle medium plate layer and 3-bottom metal, wherein P is the periodic side length of a basic unit, L1 is the side length of a L type metal patch, W1 is the width of a L type metal patch, L2 is the side length of an overlapped square, W2 is the distance of the overlapped square in vertical and horizontal translation, and H is the thickness of the medium plate layer;

FIG. 4 is a simulation result of the basic unit of the present invention, in which: fig. 4 (a) is a simulation result of homopolarization reflection amplitude of the super-surface unit, and fig. 4 (b) is a simulation result of cross-polarization reflection amplitude.

Detailed Description

The present invention will be further described with reference to the following examples.

As shown in fig. 1-3, the dual-frequency polarization conversion super-surface unit is characterized in that a basic unit comprises a surface metal structure layer 1, a middle dielectric plate layer 2 and a bottom metal layer 3 which are sequentially arranged from top to bottom, wherein the surface metal structure layer 1 comprises a first L type metal patch 11, a second L type metal patch 12 and a first overlapped square metal patch 13 which are attached to the upper surface of the upper dielectric plate layer, and the whole surface metal structure layer 1 is in a central symmetrical pattern.

The periodic side length p of the basic unit is 9-11mm, the side lengths L1 of the first L type metal patch 11 and the second L type metal patch 12 are both 4-5mm, the widths W1 are both 0.65-0.85mm, the side lengths L2 of two overlapped squares of the first overlapped square metal patch 13 are both 1-3mm, the distances W2 of vertical translation and horizontal translation of the two overlapped squares are both 1.4-1.6mm, the thickness H of the middle medium plate layer 2 is 0.8-1.0mm, the dielectric constant is 4.1-1.5, and the loss tangent is 0.000-0.006.

Preferably, the periodic side p of the basic unit is 10mm, the sides L1 of the first L-type metal patches 11 and the second L-type metal patches 12 are both 5mm, the width W1 is 0.75mm, the sides L2 of the two overlapped squares of the first overlapped square metal patches 13 are both 2mm, the distances W2 of the two overlapped squares in up-down and left-right translation are both 1.5mm, and the thickness H of the intermediate medium plate layer 2 is 0.9 mm.

Specifically, under the irradiation of the linear polarized electromagnetic wave, the reflection amplitudes of the super-surface basic unit in the same polarization direction near 8.86GHz and in the range from 14.98GHz to 16.09GHz are both less than-10 dB, and most energy of the incident wave is reflected to the cross polarization direction of the incident wave.

As shown in fig. 4, it is known from the simulation results that, when the cell is incident with the linearly polarized electromagnetic wave, the reflection amplitudes of the incident wave in the same polarization direction are both smaller than-10 dB in the vicinity of 8.86GHz and in the range of 14.98GHz to 16.09GHz in fig. 4 (a). Meanwhile, as can be seen from fig. 4 (b), in the above two frequency ranges, the reflection amplitude of the cell in the incident wave cross polarization direction is high. Simulation results show that the super-surface basic unit can efficiently convert most energy of linearly polarized incident waves to the cross polarization direction of the linearly polarized incident waves in two specific frequency ranges, and the function of dual-frequency polarization conversion is realized.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.