A design method for a frequency-selective reflection-transmission composite polarization converter

Abstract

The present invention discloses a design method for a frequency-selective reflection-transmission composite polarization converter, comprising the following steps: (1) establishing a metasurface unit composed of two layers of square substrates; (2) using the upper substrate as a reflection layer, and arranging a symmetrical double-arrow metal layer on the upper surface of the reflection layer; and arranging a "sun"-shaped structure on the lower surface of the reflection layer in a 45-degree direction; (3) using the lower substrate as a transmission layer, and arranging four rectangular metal patches on four diagonal sides of the upper surface of the transmission layer; and arranging four irregular rectangular metal patches evenly in the middle; arranging four metal vias in the middle of the upper surface of the transmission layer to connect the upper and lower surfaces, and the four metal vias are respectively connected to the four irregular rectangular metal patches; and arranging the lower surface to be a translation mirror image of the upper surface; and (4) arranging the projection layer and the reflection layer to be air-connected. The present invention can realize multiple functions such as frequency-selective polarization conversion transmission and frequency-selective polarization conversion reflection, and can also perform phase control.

Description

Technical Field

[0001] The present invention relates to the technical field of metasurface devices, and in particular to a design method of a frequency-selective reflection-transmission composite polarizer. Background Art

[0002] Transmission polarization refers to the process of changing the polarization state of the transmitted electromagnetic wave from one state to another through a certain medium or structure. This process has important application value in the fields of wireless communication, radar stealth, remote sensing detection, etc. For example, in wireless communication, by adjusting the polarization state of the electromagnetic wave, the signal transmission quality and anti-interference ability can be improved; in radar stealth, by changing the polarization state of the reflected wave, the detection probability of the radar can be reduced.

[0003] However, although transmission and reflection technologies each have significant advantages, their combination is not common in existing technologies. This is because there are certain challenges in designing and realizing an integrated structure with transmission and reflection functions, including the complexity of material selection, structural design, electromagnetic simulation and optimization, etc. In addition, the coupling effect of transmission and reflection may lead to a trade-off in performance, making the design more complicated. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a design method for a frequency-selective reflection-transmission composite polarizer to solve the disadvantages of the prior art that it is difficult to combine transmission and reflection technologies.

[0005] Technical solution: The design method of a frequency-selective reflection-transmission composite polarization converter described in the present invention comprises the following steps:

[0006] (1) Establish a metasurface unit consisting of two layers of square substrates;

[0007] (2) The upper substrate is used as a reflective layer, and a symmetrical double-arrow metal layer is set on the upper surface of the reflective layer; a "sun"-shaped structure is set on the lower surface of the reflective layer at a 45-degree direction;

[0008] (3) The lower substrate is used as a transmission layer, and four rectangular metal patches are respectively arranged at the four diagonal corners of the upper surface of the transmission layer; at the same time, four irregular rectangular metal patches are evenly arranged in the middle; four metal vias are arranged in the middle of the upper surface of the transmission layer to connect the upper and lower surfaces, and the four metal vias are respectively connected to the four irregular rectangular metal patches; the lower surface is set as a translation mirror image of the upper surface;

[0009] (4) The transmission layer and the reflection layer are set to be connected by air.

[0010] A frequency-selective reflection-transmission composite polarizer described in the present invention comprises a metasurface unit composed of two layers of square substrates; wherein the upper substrate serves as a reflection layer, and a symmetrical double-arrow metal patch is provided on the upper surface of the reflection layer; a "sun"-shaped metal patch is provided on the lower surface of the reflection layer at a 45-degree direction; the lower substrate serves as a transmission layer, and four rectangular metal patches are provided at four diagonal corners of the upper surface of the transmission layer, and four irregular rectangular metal patches are evenly arranged in the middle; four metal vias are arranged in the middle of the upper surface of the transmission layer to connect the upper and lower surfaces, and the four metal vias are respectively connected to the four irregular rectangular metal patches; the lower surface is obtained by a translational mirror image of the upper surface; the upper and lower surfaces of the transmission layer form a patch-through-hole-patch structure, and the four patch-through-hole-patch structures form four-fold rotational symmetry; the transmission layer and the reflection layer are connected by air.

[0011] Furthermore, the four irregular rectangular metal patches on the upper surface and the lower surface are obtained by cutting corners of four rectangular metal patches.

[0012] Furthermore, there are gaps between the four rectangular metal patches on the upper surface and the lower surface of the transmission layer and the edge of the transmission layer.

[0013] Furthermore, after the transmission layer is flipped, a 180° phase difference will occur in the transmission frequency band.

[0014] Furthermore, when the reflective layer is rotated 90°, a phase difference of 180° will be generated in the reflected frequency band.

[0015] Furthermore, the reflection polarization conversion rate of the metasurface is expressed as , the transmission polarization conversion rate is expressed as ,in is the co-polarization reflection coefficient, is the cross-polarization reflection coefficient, is the co-polarization transmission coefficient, is the cross-polarization transmission coefficient.

[0016] Furthermore, the transmission layer and the reflection layer are spaced 5-7 mm apart.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: it cleverly combines two layers of metasurfaces with different structures and functions together to achieve multiple functions such as frequency-selective polarization conversion transmission and frequency-selective polarization conversion reflection, while being able to perform phase control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A perspective view of the present invention;

[0019] Figure 2 is the upper surface of the reflective layer of the present invention;

[0020] Figure 3is the lower surface of the reflective layer of the present invention;

[0021] Figure 4 is the upper surface of the transmission layer of the present invention;

[0022] Figure 5 It is the S parameter curve diagram of transmission polarization conversion and reflection polarization conversion under x-polarized incident wave of the present invention;

[0023] Figure 6 It is the S parameter curve diagram of transmission polarization conversion and reflection polarization conversion under y-polarization incident wave of the present invention;

[0024] Figure 7 It is a transmission-polarization S parameter curve diagram of the present invention under x-polarized incident wave;

[0025] Figure 8 It is a reflection-polarization S parameter curve diagram of the present invention under x-polarized incident wave;

[0026] Fig. 9 It is a transmission-polarization S parameter curve diagram under y-polarized incident wave of the present invention;

[0027] Fig.10 It is a reflection-polarization S parameter curve diagram under y-polarization incident wave of the present invention.

[0028] in, Figure 1 The names of the components are: transmission layer 1, first rectangular metal patch 2, second rectangular metal patch 3, third rectangular metal patch 4, fourth rectangular metal patch 5, first irregular rectangular metal patch 6, second irregular rectangular metal patch 7, third irregular rectangular metal patch 8, fourth irregular rectangular metal patch 9, first metal via 10, second metal via 11, third metal via 12, fourth metal via 13, reflection layer 14, double-arrow metal patch 15, and "sun" shaped structure metal patch 16. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0030] like Figure 1 As shown, an embodiment of the present invention provides a frequency-selective reflection-transmission composite polarizer, which is composed of two layers of square substrates to form a supersurface unit; wherein the dielectric substrate material is other common materials such as F4B plate; the dielectric substrate of the supersurface unit is set to a square.

[0031] like Figure 2 As shown, the upper substrate serves as a reflective layer 14, and a symmetrical double-arrow metal patch 15 is provided on the upper surface of the reflective layer 14;

[0032] like Figure 3As shown, a "sun"-shaped metal patch 16 is provided at a 45-degree angle on the lower surface of the reflective layer 14;

[0033] like Figure 4 As shown, the lower substrate is used as the transmission layer 1, and four rectangular metal patches are respectively arranged at the four diagonals of the upper surface of the transmission layer 1, namely the first rectangular metal patch 2, the second rectangular metal patch 3, the third rectangular metal patch 4, and the fourth rectangular metal patch 5; four irregular rectangular metal patches are evenly arranged in the middle, namely the first irregular rectangular metal patch 6, the second irregular rectangular metal patch 7, the third irregular rectangular metal patch 8, and the fourth irregular rectangular metal patch 9; four metal vias are arranged in the middle of the upper surface of the transmission layer 1 to connect the upper and lower surfaces, namely: the first metal via 10, the second metal via 11, the third metal via 12, and the fourth metal via 13, and the four metal vias are respectively connected to the four irregular rectangular metal patches; the lower surface is obtained by translation and mirroring the upper surface; wherein, the four irregular rectangular metal patches on the upper surface and the lower surface are respectively obtained by corner cutting of the four rectangular metal patches. There is a gap between the four rectangular metal patches on the upper and lower surfaces of the transmission layer and the edge of the transmission layer.

[0034] The upper and lower surfaces of the transmission layer form a patch-through-patch structure, and the four patch-through-patch structures form a four-fold rotational symmetry; after the transmission layer is flipped, the transmission frequency band will produce a 180° phase difference. After the reflection layer is rotated 90°, the reflection frequency band will produce a 180° phase difference. The distance between the transmission layer and the reflection layer is 5-7mm. The transmission layer and the reflection layer are connected by air.

[0035] The reflection polarization conversion rate of the metasurface is expressed as , the transmission polarization conversion rate is expressed as ,in is the co-polarization reflection coefficient, is the cross-polarization reflection coefficient, is the co-polarization transmission coefficient, is the cross-polarization transmission coefficient.

[0036] The present invention optimizes the parameters of the metasurface unit and optimizes the metasurface unit of the designed metasurface device through CST simulation software.

[0037] Figure 5-Figure 6 The corresponding curve is calculated by simulation. The structure is used to obtain a polarization conversion rate and transmission efficiency of more than 90% around 8.3GHz to 10.3GHz. In addition, the device is insensitive to linear polarization and has a good polarization conversion rate and transmission efficiency in this frequency band for incident waves with any polarization angle.

[0038] Figure 7-10The S parameters of the x-polarization transmission / reflection and y-polarization transmission / reflection that adjust some structural parameters in the iterative unit structure.

[0039] The embodiment of the present invention also provides a method for designing a frequency-selective reflection-transmission composite polarization converter, comprising the following steps:

[0040] (1) Establish a metasurface unit consisting of two layers of square substrates;

[0041] (2) The upper substrate is used as a reflective layer, and a symmetrical double-arrow metal layer is set on the upper surface of the reflective layer; a "sun"-shaped structure is set on the lower surface of the reflective layer at a 45-degree direction;

[0042] (3) The lower substrate is used as a transmission layer, and four rectangular metal patches are respectively arranged at the four diagonal corners of the upper surface of the transmission layer; at the same time, four irregular rectangular metal patches are evenly arranged in the middle; four metal vias are arranged in the middle of the upper surface of the transmission layer to connect the upper and lower surfaces, and the four metal vias are respectively connected to the four irregular rectangular metal patches; the lower surface is set as a translation mirror image of the upper surface;

[0043] (4) The reflective layer and the transmissive layer are set to be connected by air.

Claims

1. A design method for a frequency-selective reflection-transmission composite polarization converter, characterized in that: The following steps are involved: (1) The metasurface unit is composed of two layers of square substrates; (2) The upper substrate is used as a reflective layer, and a symmetrical double-arrow metal layer is set on the upper surface of the reflective layer; a "sun"-shaped metal patch is set on the lower surface of the reflective layer at a 45-degree direction; (3) The lower substrate is used as a transmission layer, and four rectangular metal patches are respectively set at the four diagonal corners of the upper surface of the transmission layer; at the same time, four irregular rectangular metal patches are evenly set in the middle; four metal vias are set in the middle of the upper surface of the transmission layer to connect the upper and lower surfaces, and the four metal vias are respectively connected to the four irregular rectangular metal patches; the lower surface is set as a translation mirror image of the upper surface; the four irregular rectangular metal patches on the upper and lower surfaces are respectively obtained by cutting off one rectangular corner of the four rectangular metal patches; (4) The transmission layer and the reflection layer are set to be connected by air.

2. A frequency-selective reflection-transmission composite polarization converter, characterized in that: A metasurface unit is composed of two layers of square substrates; wherein, the upper substrate serves as a reflective layer, and a symmetrical double-arrow metal patch is provided on the upper surface of the reflective layer; a "sun"-shaped metal patch is provided at a 45-degree direction on the lower surface of the reflective layer; the lower substrate serves as a transmission layer, and four rectangular metal patches are provided at four diagonals on the upper surface of the transmission layer, and four irregular rectangular metal patches are evenly arranged in the middle; four metal vias are arranged in the middle of the upper surface of the transmission layer to connect the upper and lower surfaces, and the four metal vias are respectively connected to the four irregular rectangular metal patches; the lower surface is obtained by the translational mirror image of the upper surface; the upper and lower surfaces of the transmission layer form a patch-through-hole-patch structure, and the four patch-through-hole-patch structures form a four-fold rotational symmetry; the transmission layer and the reflective layer are connected by air; wherein, the four irregular rectangular metal patches on the upper and lower surfaces are respectively obtained by cutting off a rectangular corner of four rectangular metal patches.

3. The frequency-selective reflection-transmission composite polarization converter according to claim 2, characterized in that: There are gaps between the four rectangular metal patches on the upper and lower surfaces of the transmission layer and the edge of the transmission layer.

4. The frequency-selective reflection-transmission composite polarization converter according to claim 2, characterized in that: After the transmission layer is flipped, the transmission frequency band will produce a 180° phase difference.

5. The frequency-selective reflection-transmission composite polarization converter according to claim 2, characterized in that: After the reflective layer rotates 90°, the reflected frequency band will produce a 180° phase difference.

6. The frequency-selective reflection-transmission composite polarization converter according to claim 2, characterized in that: The reflection polarization conversion rate of the metasurface is expressed as , the transmission polarization conversion rate is expressed as ,in is the co-polarization reflection coefficient, is the cross-polarization reflection coefficient, is the co-polarization transmission coefficient, is the cross-polarization transmission coefficient.

7. The frequency-selective reflection-transmission composite polarization converter according to claim 2, characterized in that: The distance between the transmission layer and the reflection layer is 5-7mm.

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