A dual-polarization 1-bit phase-modulated flexible electromagnetic reflective metasurface structure

Abstract

The present invention relates to a dual-polarization 1-bit phase-modulated flexible electromagnetic reflection metasurface structure, comprising a plurality of units arranged in a rectangular array, wherein the units include a metal resonance pattern layer, a flexible dielectric substrate layer located on the metal resonance pattern layer, an epoxy adhesive layer bonded to the flexible dielectric substrate layer, a shaping foam dielectric layer bonded to the side of the epoxy adhesive layer facing away from the flexible dielectric substrate layer, and a metal stratum bonded to the side of the shaping foam dielectric layer facing away from the epoxy adhesive layer. The present invention has the advantages of being able to effectively control the phases of horizontally polarized and vertically polarized electromagnetic waves in the X-band and being applicable to serve some specific curved surface occasions.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic reflection metasurfaces, and specifically relates to a dual-polarization 1-bit phase-modulated flexible electromagnetic reflection metasurface structure. Background Art

[0002] With the development of modern cities and communication technology, electromagnetic waves are easily affected by the environment during propagation in various types of urban buildings. Problems such as poor diffraction ability and large penetration loss need to be solved. Metasurfaces can be studied and adapted to these complex environments because of their low cost, low energy consumption, low profile and light weight. Their effective control of electromagnetic wave polarization, phase and amplitude also provides a solution for signal blindness in urban environments and complex indoor environments. For some indoor dead corners and arched exterior walls and curved decoration scenes, dual-polarization flexible metasurfaces can more efficiently achieve the unification of signal blindness and environmental appearance requirements. For cylindrical structural components with different curvatures, such as aircraft fuselages, high-scattering arched parts of ocean-going ships and other curved structures, dual-polarization flexible metasurfaces can achieve effective control of horizontally polarized and vertically polarized electromagnetic waves without changing the external aerodynamic characteristics of the curved carrier, meeting the functions of receiving, sending and RCS reduction of ship signals in the vast ocean.

[0003] In recent years, flexible reconfigurable electromagnetic reflective metasurfaces that can freely control the phase of dual-polarized electromagnetic waves have attracted widespread attention from researchers. This embodiment using a flexible material substrate and a dual-polarization electrical adjustment method provides some solutions to the conformal requirements of electromagnetic metasurfaces. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a phase-encoded absorption-scattering metasurface that can effectively control the phase of horizontally polarized and vertically polarized electromagnetic waves in the X-band and can be applied to serve some specific curved surface occasions.

[0005] The technical solution of the present invention is as follows:

[0006] A dual-polarization 1-bit phase-modulated flexible electromagnetic reflection metasurface structure comprises a plurality of units arranged in a rectangular array, wherein the units comprise a metal resonance pattern layer, a flexible dielectric substrate layer located on the metal resonance pattern layer, an epoxy adhesive layer bonded to the flexible dielectric substrate layer, a shaping foam dielectric layer bonded to the side of the epoxy adhesive layer facing away from the flexible dielectric substrate layer, and a metal ground layer bonded to the side of the shaping foam dielectric layer facing away from the epoxy adhesive layer.

[0007] Further, the metal resonant pattern layer is composed of two pairs of rectangular patches symmetrical along the diagonal of the flexible dielectric substrate layer, each pair of rectangular patches includes a first rectangular patch, a second rectangular patch and a third rectangular patch, and the first rectangular patch and the second rectangular patch are arranged in the same direction and the length of the first rectangular patch is less than the length of the second rectangular patch, the length direction of the third rectangular patch is perpendicular to the length direction of the second rectangular patch, and the first rectangular patch, the second rectangular patch or the third rectangular patch in two adjacent polarization directions are connected at equal intervals by three extension lines with an angle of 45°, wherein the extension line of one unit can be connected to the first rectangular patch, the second rectangular patch or the third rectangular patch of another unit;

[0008] The first rectangular patch is connected to a PIN diode connected to the second rectangular patch.

[0009] Further, the lengths of the first rectangular patch, the second rectangular patch and the third rectangular patch are PL2, PL1 and PL3 respectively, and the length relationship between the first rectangular patch, the second rectangular patch and the third rectangular patch satisfies PL1=PL2+PL3.

[0010] Furthermore, the first rectangular patch, the second rectangular patch and the third rectangular patch have the same width.

[0011] Furthermore, the flexible dielectric substrate layer is made of SH260 ​​flexible sheet material.

[0012] Furthermore, the thickness of the flexible dielectric substrate layer is in the range of 0.8-1.5 mm.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The present invention realizes the conformal requirement of high adaptability through a thin and light flexible dielectric substrate layer and a variously prepared plastic foam dielectric layer. At the same time, by regulating the conduction and disconnection of two PIN diodes in the horizontal and vertical polarization directions, a control effect of a 180°±20° phase difference between the two polarized waves is achieved, thereby improving the control freedom. According to the concept of the coded metasurface, the unit states under different resonances are defined as a "0" state and a "1" state. Application functions such as beam scanning and RCS reduction can be realized through array coding.

[0015] 2. The preparation process of the present invention is simple, and a complex curved surface shaped foam dielectric layer with a fixed thickness can be prepared according to different needs. At the same time, a metal resonant pattern layer is etched and printed on the flexible dielectric substrate layer, and it is bonded to the metal stratum. This method is in line with the post-installation process, and the complex curved surface structure can be determined first. The array design has a high degree of freedom, which makes the widespread application and popularization of the flexible electromagnetic reflection supersurface structure possible.

[0016] 3. The present invention uses extended lines with specific spacing and width to connect with rectangular patches to achieve a relative bandwidth of 12.6% in the X-band, covering the operating frequency of some X-band radars. Based on this new surface resonance structure, it can be optimized to other bands to meet some scenarios that require dual-polarization flexible metasurface structures, such as signal enhancement of indoor and outdoor curved scenes.

[0017] In summary, the present invention has the advantages of effectively regulating the phase of horizontally polarized and vertically polarized electromagnetic waves in the X-band and can be applied to serve some specific curved surface occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram of the invented metasurface structure;

[0019] Figure 2 The present invention Figure 1 Schematic diagram of the unit structure in;

[0020] Figure 3 The present invention Figure 2 Schematic diagram of the metal resonance pattern layer structure;

[0021] Figure 4 is a reflection phase diagram of horizontally polarized waves and vertically polarized waves of the metasurface unit in the embodiment of the present invention in the 8-12 GHz frequency band;

[0022] Figure 5 It is a reflection amplitude response diagram of horizontally polarized waves and vertically polarized waves of the metasurface unit described in an embodiment of the present invention in the 8-12 GHz frequency band.

[0023] In the figure, 1. metal resonant pattern layer, 2. flexible dielectric substrate layer, 3. epoxy adhesive layer, 4. plastic foam dielectric layer, 5. metal ground layer, 6. extension line, 7. rectangular patch, 8. PIN diode. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1-5As shown, a dual-polarization 1-bit phase-modulated flexible electromagnetic reflection metasurface structure includes a plurality of units arranged in a rectangular array, wherein the units include a metal resonant pattern layer 1, a flexible dielectric substrate layer 2 located on the metal resonant pattern layer 1, an epoxy adhesive layer 3 bonded to the flexible dielectric substrate layer 2, a plastic foam dielectric layer 4 bonded to the side of the epoxy adhesive layer 3 facing away from the flexible dielectric substrate layer 2, and a metal ground layer 5 bonded to the side of the plastic foam dielectric layer 4 facing away from the epoxy adhesive layer 3;

[0026] The metal resonant pattern layer 1 is printed on the flexible dielectric substrate layer 2 by means of a printed circuit board etching process, and then the metal resonant pattern layer 1 is bonded to the top of the plastic foam dielectric layer 4 by means of an epoxy adhesive layer 3;

[0027] The metal resonance pattern layer 1 can be printed on any surface of the flexible dielectric substrate layer 2, and the plastic foam dielectric layer 4 is a plastic foam, and the thickness of the plastic foam dielectric layer 4 is in the range of 1.2-2 mm, which can be adjusted according to the actual conformal scenario, which can not only provide actual support and protection but also widen the resonance frequency and improve the working bandwidth of the unit structure.

[0028] In this embodiment, the metal resonant pattern layer 1 is composed of two pairs of rectangular patches 7 symmetrical along the diagonal line of the flexible dielectric substrate layer 2, each pair of rectangular patches 7 includes a first rectangular patch 7, a second rectangular patch 7 and a third rectangular patch 7, and the first rectangular patch 7 and the second rectangular patch 7 are arranged in the same direction and the length of the first rectangular patch 7 is less than the length of the second rectangular patch 7, the length direction of the third rectangular patch 7 is perpendicular to the length direction of the second rectangular patch 7, and the first rectangular patch 7, the second rectangular patch 7 or the third rectangular patch 7 in two adjacent polarization directions are connected at equal intervals by three extension lines 6 with an angle of 45°, so as to achieve the widening of the effective resonant frequency of the unit, wherein the extension line 6 of one unit can be connected to the first rectangular patch 7, the second rectangular patch 7 or the third rectangular patch 7 of another unit;

[0029] The first rectangular patch 7 is connected to a PIN diode 8 connected to the second rectangular patch 7, and the phases of the two reflected polarized waves are controlled by controlling the on and off of the PIN diode 8;

[0030] As a preferred method, the PIN diode 8 of the SMP1320-040LF_SN1 model is selected, which makes the cost extremely low and has extremely high economic value in the production and processing process;

[0031] By applying reconfigurable technology on flexible metasurface units, the practical versatility of the structure is expanded.

[0032] In this embodiment, the lengths of the first rectangular patch 7, the second rectangular patch 7 and the third rectangular patch 7 are PL2, PL1 and PL3 respectively, the length relationship between the first rectangular patch 7, the second rectangular patch 7 and the third rectangular patch 7 satisfies PL1=PL2+PL3, and the widths of the first rectangular patch 7, the second rectangular patch 7 and the third rectangular patch 7 are the same.

[0033] In this embodiment, the material of the flexible dielectric substrate layer 2 is SH260 ​​flexible plate, and the thickness of the flexible dielectric substrate layer 2 is in the range of 0.8-1.5 mm;

[0034] like Figure 3 As shown, in this embodiment, P is defined as the period length of the unit structure. On the basis of not generating grating lobes, the design range of the conformal metasurface structure is 0.43–0.46 times the wavelength.

[0035] The central frequency point of the metasurface of the present invention is 10.3 GHz, and the operating frequency band is 9.6-11 GHz.

[0036] like Figure 3 As shown, the length and width of the two second rectangular patches 7 symmetrically located at the center of the metal resonant pattern layer 1 are determined by PL1 and PW, and the lengths of the two first rectangular patches 7 and the third rectangular patches 7 symmetrically located at the center from the upper left to the lower right are determined by PL2 and PL3 respectively, and the widths are also determined by PW. The length relationship between the first rectangular patch 7, the second rectangular patch 7 and the third rectangular patch 7 in a single polarization direction satisfies PL1=PL2+PL3, that is, under the combination of two adjacent units, the patches corresponding to PL2 and PL3 are the same as the rectangular patch 7 corresponding to PL1 after combination;

[0037] PD2 and PD1 respectively represent the distance between the extension line 6 and the edge on the second rectangular patch 7 and the interval therebetween. W1 represents the width of all extension lines 6. The unit bandwidth can be optimized by adjusting the PD1 interval. By continuously adjusting the size parameters of PL1, PL2, PL3, PD1, PD2, W1, PW and P, the phase control accuracy and operating frequency band of the unit can be effectively optimized.

[0038] In order to intuitively demonstrate the phase control capability of the unit structure within the working frequency band, the present invention imports the S2P files of the PIN diode 8 in two states, and obtains the S11 parameters of the unit structure in the horizontal polarization and vertical polarization directions at 8-12 GHz in the CST commercial simulation software. The reflection amplitude and phase shift results are shown in Figure 2. Figure 4 and Figure 5As shown, the flexible metasurface unit achieves a reflection phase difference of 180°±20° between two polarized waves in the frequency range of 9.6–11 GHz, and the unit insertion loss is within 2 dB. The flexible electromagnetic reflection metasurface has a good phase control effect within the designed frequency band, with small insertion loss and high polarization isolation, which meets the needs of practical applications.

[0039] in Figure 3 The parameters are P=14;PL1=5.35;PL2=2.85;PL4=2.5;PD1=1.25;PD2=0.75;PW=1.2;W1=0.2. All parameters can be adjusted appropriately to change the working frequency band, but the overall structure must not be affected. PL1=PL2+PL3 must be satisfied, and PW <P-(2*PL1-0.6)。

[0040] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-polarization 1-bit phase-modulated flexible electromagnetic reflection metasurface structure, characterized in that: The invention comprises a plurality of units arranged in a rectangular array, wherein the units include a metal resonant pattern layer, a flexible dielectric substrate layer located on the metal resonant pattern layer, an epoxy adhesive layer bonded to the flexible dielectric substrate layer, a plastic foam dielectric layer bonded to the side of the epoxy adhesive layer facing away from the flexible dielectric substrate layer, and a metal ground layer bonded to the side of the plastic foam dielectric layer facing away from the epoxy adhesive layer; The metal resonant pattern layer is composed of two pairs of rectangular patches symmetrical along the diagonal line of the flexible dielectric substrate layer, each pair of rectangular patches includes a first rectangular patch, a second rectangular patch and a third rectangular patch, and the first rectangular patch and the second rectangular patch are arranged in the same direction and the length of the first rectangular patch is less than the length of the second rectangular patch, the length direction of the third rectangular patch is perpendicular to the length direction of the second rectangular patch, and the first rectangular patch, the second rectangular patch or the third rectangular patch in two adjacent polarization directions are connected at equal intervals by three extension lines with an angle of 45°, wherein the extension line of one unit can be connected to the first rectangular patch, the second rectangular patch or the third rectangular patch of another unit; The first rectangular patch is connected to a PIN diode connected to the second rectangular patch.

2. According to claim 1, a dual-polarization 1-bit phase-modulated flexible electromagnetic reflective metasurface structure is characterized by: The lengths of the first rectangular patch, the second rectangular patch and the third rectangular patch are PL2, PL1 and PL3 respectively, and the length relationship between the first rectangular patch, the second rectangular patch and the third rectangular patch satisfies PL1=PL2+PL3.

3. The dual-polarization 1-bit phase-modulated flexible electromagnetic reflective metasurface structure according to claim 2, characterized in that: The first rectangular patch, the second rectangular patch and the third rectangular patch have the same width.

4. The dual-polarization 1-bit phase-modulated flexible electromagnetic reflective metasurface structure according to claim 1, characterized in that: The flexible dielectric substrate layer is made of SH260 ​​flexible sheet material.

5. The dual-polarization 1-bit phase-modulated flexible electromagnetic reflective metasurface structure according to claim 4, characterized in that: The thickness of the flexible dielectric substrate layer is in the range of 0.8-1.5 mm.

Images