A dual-polarized angular selective surface structure with wide passband angle and out-of-band drop

Abstract

The application discloses a dual-polarization angle-selective surface structure with a wide passband angle and an out-of-band drop, which is composed of a plurality of periodic units connected with each other, each periodic unit is provided with at least two metal structure layers from top to bottom, and an air medium layer unit is arranged between adjacent metal structure layers; wherein the metal structure layer comprises a dielectric substrate, an upper surface metal layer and a lower surface metal layer are arranged on the upper and lower surfaces of the dielectric substrate respectively, the upper surface metal layer and the lower surface metal layer are connected through metal vias arranged in the dielectric substrate; the upper surface metal layer and the lower surface metal layer are of the same structure, each periodic unit comprises Jerusalem-type metal sheets distributed in a circumferential direction around the center of the dielectric substrate; the arms of the Jerusalem-type metal sheets are connected with each other; the central through hole of the cross metal main arm of the Jerusalem-type metal sheet is the end of the metal via, and the metal via connects the central part of the cross metal main arm at the corresponding positions on the upper and lower surfaces of the dielectric substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic wave filtering, and in particular to a dual-polarized angle selective surface with wide passband angle and out-of-band steep drop characteristics. BACKGROUND

[0002] In the past few decades, controlling the propagation of electromagnetic waves has been a hot topic for scientists, including the selection of the frequency, polarization and incident angle of electromagnetic waves. The theory and structural design related to the frequency filtering and polarization selection of electromagnetic waves have made great progress, while the analysis and design of the selection of the incident angle of electromagnetic waves have relatively developed slowly.

[0003] The angle selective surface structure is generally an array structure periodically arranged in one or two dimensions, allowing electromagnetic waves to be transmitted at a certain angle of incidence and reflecting electromagnetic waves of other angles of incidence. This characteristic makes it widely used in the field of microwaves, such as sidelobe suppression of antennas, angle selective absorber, high efficiency energy capture, anti-jamming communication, transmitter angle control, etc. The current design method of angle selective surface structure is mainly based on the extraction of equivalent impedance or equivalent medium parameters. This method needs to extract the equivalent impedance or medium parameters on the basis of calculating the reflection transmission coefficient of the angle selective surface structure, and finally further design based on the equivalent impedance or medium parameters. Since the corresponding relationship between the geometric structure and the equivalent impedance or medium parameters cannot be directly determined for any periodic structure, the design method based on the extraction of equivalent impedance or medium parameters is relatively cumbersome.

[0004] In practical applications, dual-polarized electromagnetic waves often need to be controlled simultaneously, but most of the current angle selective surface structures can only control the incidence of single-polarized electromagnetic waves, and the research on the simultaneous control of dual-polarized electromagnetic waves is relatively less. The angle selective surface structure with wide passband angle is used in antennas, which can reduce the loss of effective radiation of the antenna and increase the integration and portability of the communication system. However, the passband angle of the angle selective structure that can simultaneously control dual-polarized electromagnetic waves is relatively narrow, and the maximum can only reach 25°. The angle selective surface structure with out-of-band steep drop is used in antennas, which can effectively suppress the sidelobe of the antenna and improve the directivity and anti-interference ability of the antenna. Therefore, how to efficiently design an angle selective surface structure with wide passband angle, high selectivity and polarization insensitivity is a problem to be solved. SUMMARY

[0005] The purpose of the present application is to provide a dual-polarized angle selective surface structure with wide passband angle and out-of-band steep drop, which can solve the problems of narrow passband angle and poor out-of-band steep drop to some extent.

[0006] In order to achieve the above-mentioned task, the present application adopts the following technical solutions:

[0007] A dual-polarized angular selective surface structure with wide passband angle and out-of-band steep drop is formed by a plurality of periodic units connected to each other, each periodic unit being provided with at least two metal structure layers from top to bottom, and an air dielectric layer unit being arranged between adjacent metal structure layers.

[0008] The metal structure layer comprises a dielectric substrate, and an upper surface metal layer and a lower surface metal layer are arranged on the upper and lower surfaces of the dielectric substrate respectively, and the upper surface metal layer and the lower surface metal layer are connected through a metal via hole formed in the dielectric substrate; the upper surface metal layer and the lower surface metal layer have the same structure, and each periodic unit comprises Jerusalem metal pieces distributed circumferentially around the center of the dielectric substrate, the Jerusalem metal pieces are cross-shaped structures comprising a cross metal main arm and four branch arms perpendicularly arranged at the ends of the cross metal main arm respectively; the branch arms of the Jerusalem metal pieces of each periodic unit are connected to each other; the middle hole of the cross metal main arm is the end of the metal via hole, and the metal via hole connects the cross metal main arm in the corresponding positions on the upper and lower surfaces of the dielectric substrate.

[0009] Further, the branch arms of the Jerusalem metal pieces form a 45° angle with the edges of the dielectric substrate of the periodic unit.

[0010] Further, the metal structure layer is provided with two layers, a first layer metal structure layer and a second layer metal structure layer equivalent to microwave network A and microwave network B, the reflection coefficient of the first layer metal structure layer representing the scattering parameter of microwave network A The phase is represented as The reflection coefficient of the second layer metal structure layer represents the scattering parameter of microwave network B The phase is represented as

[0011] At the wave-transparent angle θ0, the amplitude of the reflection coefficient of the first layer metal structure layer and the second layer metal structure layer satisfies: The thickness of the air dielectric layer between the first layer metal structure layer and the second layer metal structure layer satisfies Where k is the wave number of the working frequency; at the reflection angle θ r , the reflection coefficient of the first layer metal structure layer and the second layer metal structure layer satisfies

[0012] Further, the specific determination method of the thickness h2 of the air dielectric layer is as follows:

[0013] First, the structure parameters of the metal structure layer in the angular selective surface structure are determined;

[0014] Secondly, the electromagnetic simulation software is used to simulate modeling and simulation calculation on the angle selection surface structure with the determined structure parameters; in the calculation, the reflection coefficient amplitude of the first layer metal structure layer under the preset polarization mode is simulated and calculated when the electromagnetic wave is incident at 0°-80°, and the wave-transparent angle range is determined based on the reflection coefficient value in the simulation calculation result; a series of air medium layer thicknesses h2 corresponding to each wave-transparent angle in the wave-transparent angle range are calculated at different values of the parameter m under the preset polarization mode; wherein, the preset polarization mode is TE polarization or TM polarization.

[0015] Finally, after obtaining h2 corresponding to each wave-transparent angle under two different polarization modes respectively, h2 satisfying the transmission coefficient of the electromagnetic wave incident angle under two different polarization modes is selected as the finally determined air medium layer thickness; wherein, the range of the electromagnetic wave incident angle is the wave-transparent angle range.

[0016] Further, the metal structure layer is provided with four layers, the four layers of metal structure layers have the same structure, and the first and second layers of metal structure layers and the third and fourth layers of metal structure layers have the same structure of the first and third layers of air medium layers.

[0017] Further, the first layer of metal structure layer to the second layer of metal structure layer are combined, denoted as a combination structure C, the combination structure C is equivalent to a microwave network C, and the reflection coefficient of the combination structure C can be characterized as the scattering parameter of the microwave network C The phase is represented as The third layer of metal structure layer to the fourth layer of metal structure layer are combined and denoted as a combination structure D, the combination structure D is equivalent to a microwave network D, and the reflection coefficient of the combination structure D is characterized as the scattering parameter of the microwave network D The phase is represented as At the wave-transparent angle θ0, the reflection coefficient amplitudes of the combination structure C and the combination structure D satisfy: The thickness of the air medium layer between them should satisfy m=0,±1,±2,…; at the reflection angle θ r , the reflection coefficients of the combination structure C and the combination structure D satisfy

[0018] Further, the dielectric substrate adopts a square plate material with a relative dielectric constant of 2.08, the side length P of the periodic unit is 16 mm, and the thickness h1 of the dielectric substrate is 1.6 mm; the length L1 of each main arm of the cross metal main arm in the Jerusalem type metal sheet is 10 mm, the width W1 of the main arm is 2 mm; the length L2 of the branch arm is 8 mm, the width W2 of the branch arm is 3 mm; and the metal via radius r1 is 1 mm.​

[0019] Further, the thickness of the first layer air medium layer and the third layer air medium layer is h2=23mm.

[0020] Further, the thickness of the second layer air medium layer is h3=23mm.

[0021] Compared with the prior art, the present application has the following technical features:

[0022] 1. In the present application, only the reflection coefficient parameter of the metal structure layer needs to be calculated, without the need of equivalent impedance or equivalent parameter extraction, and the design process is simple.

[0023] 2. The present application can realize efficient wave transmission of the TE and TM polarized wide-band angle incident electromagnetic waves, and the passband angle reaches 40°.

[0024] 3. The angle selection structure surface has good out-of-band steepness. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The present application provides a schematic diagram of the angle selection surface structure when two metal structure layers are arranged;

[0026] Figure 2 The present application provides a top view of the Jerusalem type metal sheet of the angle selection surface structure;

[0027] Figure 3 The present application provides a three-dimensional view of the metal structure layer of the angle selection surface structure;

[0028] Figure 4 The present application provides a schematic diagram of the angle selection surface structure when four metal structure layers are arranged;

[0029] Figure 5 The present application provides a side view of the overall structure of the angle selection surface structure;

[0030] Figure 6 The present application provides a microwave network schematic diagram of the angle selection surface structure when two metal structure layers are arranged;

[0031] Figure 7 The present application provides a microwave network schematic diagram of the combination structure C and the combination structure D of the angle selection surface structure;

[0032] Figure 8 The reflection coefficient phase of the metal structure layer described in embodiment 1 when the electromagnetic wave is incident at 0°-40°;

[0033] Figure 9The reflection coefficient phase of the combined structure C described in Embodiment 2 when electromagnetic waves are incident at 0°-40°, wherein (a) is the reflection coefficient phase of the combined structure C when TE polarized electromagnetic waves are incident; and (b) is the reflection coefficient phase of the combined structure C when TM polarized electromagnetic waves are incident.

[0034] Figure 10 The transmission coefficient of the angle-selective surface structure described in Embodiment 1 for TE and TM polarized electromagnetic waves at a working frequency of 9.35 GHz, wherein (a) is the transmission coefficient of the angle-selective surface structure when TE polarized electromagnetic waves are incident; and (b) is the transmission coefficient of the angle-selective surface structure when TM polarized electromagnetic waves are incident.

[0035] Figure 11 The reflection coefficient phase of the combined structure C described in Embodiment 2 when electromagnetic waves are incident at 0°-40°, wherein (a) is the reflection coefficient phase of the combined structure C when TE polarized electromagnetic waves are incident; and (b) is the reflection coefficient phase of the combined structure C when TM polarized electromagnetic waves are incident.

[0036] Figure 12 The reflection coefficient amplitude of the combined structure C described in Embodiment 2 when electromagnetic waves are incident at 0°-80°, wherein (a) is the reflection coefficient amplitude of the combined structure C when TE polarized electromagnetic waves are incident; and (b) is the reflection coefficient amplitude of the combined structure C when TM polarized electromagnetic waves are incident.

[0037] Figure 13 The transmission coefficient of the angle-selective surface structure described in Embodiment 2 for TE and TM polarized electromagnetic waves at a working frequency of 9.35 GHz, wherein (a) is the transmission coefficient of the angle-selective surface structure when TE polarized electromagnetic waves are incident; and (b) is the transmission coefficient of the angle-selective surface structure when TM polarized electromagnetic waves are incident.

[0038] Label explanation in the figure: 1 metal structure layer, 2 air medium layer, 11 medium substrate, 12 metal via, 13 Jerusalem type metal sheet, 131 cross metal main arm, 132 branch arm. DETAILED DESCRIPTION

[0039] The present application provides a dual-polarized angle-selective surface structure with a wide passband angle and a steep drop outside the band, which only needs to adjust the reflection coefficient of the metal structure layer to satisfy the amplitude equal relationship, and the thickness of the air medium layer to satisfy the reflection coefficient phase and relationship, so as to obtain the angle-selective surface at the specified angle; the structure can realize a wide passband angle and good out-of-band cutoff characteristics when TE and TM polarized electromagnetic waves are incident.

[0040] Referring to the attached Figure 1 and 2 The angle-selective surface structure provided by the present application is composed of a plurality of periodic units connected to each other, each periodic unit is provided with at least two metal structure layers from top to bottom, and an air medium layer is arranged between adjacent metal structure layers.

[0041] The metal structure layer comprises a dielectric substrate, upper and lower surfaces of the dielectric substrate are respectively provided with an upper surface metal layer and a lower surface metal layer, the upper surface metal layer and the lower surface metal layer are connected through a metal via hole provided in the dielectric substrate; the upper surface metal layer and the lower surface metal layer are completely identical in structure, each periodic unit comprises a Jerusalem metal sheet distributed in a circumferential direction around the center of the dielectric substrate, referring to Figure 2 , the Jerusalem metal sheet is a cross structure comprising a cross metal main arm and four branch arms vertically located at the ends of the cross metal main arm respectively; the branch arms of the Jerusalem metal sheet form an angle of 45° with the edges of the dielectric substrate of the periodic unit, and the branch arms of the Jerusalem metal sheet of each periodic unit are connected with each other. The through hole in the middle of the cross metal main arm is the end of the metal via hole, and the metal via hole connects the cross metal main arms in the corresponding positions on the upper and lower surfaces of the dielectric substrate.

[0042] Scheme one:

[0043] Referring to Figure 1 , it is a structural schematic diagram of the application when two metal structure layers are adopted.

[0044] The first layer metal structure layer and the second layer metal structure layer can be respectively characterized by a microwave network A and a microwave network B, the reflection coefficient of the first layer metal structure layer can be characterized by the scattering parameter of the microwave network A The phase is represented as The reflection coefficient of the second layer metal structure layer can be characterized by the scattering parameter of the microwave network B The phase is represented as The thickness of the air dielectric layer between the first layer metal structure layer and the second layer metal structure layer is h2; at the wave transmission angle θ0, the reflection coefficient amplitudes of the first layer metal structure layer and the second layer metal structure layer satisfy: The thickness of the air dielectric layer between the first layer metal structure layer and the second layer metal structure layer should satisfy Wherein, k is the wave number of the working frequency; at the reflection angle θ r , the reflection coefficients of the first layer metal structure layer and the second layer metal structure layer satisfy In order to ensure that the reflection coefficient amplitudes of the microwave network A and the microwave network B are always equal, the method of completely identical structure of the first layer metal structure layer and the second layer metal structure layer is adopted here.

[0045] In this embodiment, the specific determination method of the air dielectric layer thickness h2 is as follows:

[0046] Firstly, the structure parameters of the metal structure layer in the angle selection surface structure are determined, including the dielectric constant, shape, side length, thickness of the dielectric substrate, the length and width of the cross metal main arm in the Jerusalem type metal sheet, the length and width of the branch arm, and the radius of the metal via;

[0047] Secondly, the angle selection surface structure with the determined structure parameters is simulated and calculated by using an electromagnetic simulation software; in the calculation, the reflection coefficient amplitude of the first layer metal structure layer under a preset polarization mode when the electromagnetic wave is incident at 0°-80° is simulated and calculated, and based on the numerical value of the reflection coefficient in the simulation calculation result, the wave-transparent angle range is determined; the formula is used to calculate a series of air medium layer thicknesses h2 corresponding to each wave-transparent angle in the wave-transparent angle range at different values of the parameter m under the preset polarization mode; wherein the preset polarization mode is TE polarization or TM polarization.

[0048] Finally, after obtaining the h2 corresponding to each wave-transparent angle under two different polarization modes respectively, the h2 satisfying the transmission coefficients of the electromagnetic wave incident angles under the two different polarization modes is selected as the finally determined air medium layer thickness; wherein the range of the electromagnetic wave incident angle is the wave-transparent angle range.

[0049] Scheme two:

[0050] In another embodiment of the present application is a four-layer metal structure layer structure, as shown in Figure 5 ; wherein the four-layer metal structure layers have the same structure, and the first and second layer metal structure layers and the third and fourth layer metal structure layers have the same structure of the first and third layer air medium layers.

[0051] As shown in Figure 7 , the first layer metal structure layer to the second layer metal structure layer are combined, denoted as a combined structure C, the combined structure C can be characterized as a microwave network C, and the reflection coefficient of the combined structure C can be characterized as the scattering parameter of the microwave network C, and the phase is denoted as The third layer metal structure layer to the fourth layer metal structure layer are combined, denoted as a combined structure D, the combined structure D can be regarded as a microwave network D, and the reflection coefficient of the combined structure D can be characterized as the scattering parameter of the microwave network D, and the phase is denoted as At the wave-transparent angle θ0, the reflection coefficient amplitudes of the combined structure C and the combined structure D satisfy: The thickness of the air medium layer between them should satisfy At the reflection angle θ r , the reflection coefficients of the combined structure C and the combined structure D satisfy To ensure that the reflection coefficient amplitudes of microwave network C and microwave network D are always equal, the same method as that of combination structure C and combination structure D is adopted here, that is, the structures of the metal structure layers in this scheme are the same, and the structures (thicknesses) of the air medium layers between the first and second metal structure layers and between the third and fourth metal structure layers are the same.

[0052] In this scheme, the thickness h3 of the second layer air medium layer between combination structure C and combination structure D is determined in a similar manner to that of scheme one, that is, combination structure C and combination structure D are respectively regarded as the first layer metal structure layer and the second layer metal structure layer of scheme one for calculation.

[0053] Embodiment 1:

[0054] Reference Figures 1 to 3 In this embodiment, the structure of two metal structure layers is given, and the related design of the metal structure layer and the air medium layer therebetween is described above and will not be repeated here. The schematic diagram of the microwave network of this structure can be referred to Figure 6 , wherein the first layer metal structure layer is characterized by microwave network A, the second layer metal structure layer is characterized by microwave network B, and the air medium layer is characterized by a transmission line with a length of h2; since the first layer metal structure layer and the second layer metal structure layer are completely the same, the reflection coefficients of the two microwave networks satisfy the condition of equal amplitude

[0055] In this embodiment, the dielectric substrate of the metal structure layer adopts a square plate with a relative dielectric constant of 2.08, the period (edge length) P of the period unit is 16 mm, and the thickness h1 of the dielectric substrate is 1.6 mm; see Figure 3 , the length L1 of each main arm of the Jerusalem type metal sheet is 10 mm, the width W1 of the main arm is 2 mm; the length L2 of the branch arm is 8 mm, and the width W2 of the branch arm is 3 mm; the radius r1 of the metal via is 1 mm.

[0056] Based on the commercial electromagnetic simulation software ANSYS HFSS2023R1, the reflection coefficient phase of the first layer metal structure layer in embodiment 1 under the TE polarization mode and the TM polarization mode under the 0° incidence of the incident wave is simulated and calculated, and the calculation result can be referred to Figure 8 ; the reflection coefficient amplitude of the first layer metal structure layer under the TE polarization or TM polarization electromagnetic wave under the 0°-80° incidence is simulated and calculated, and the calculation result can be referred to Figure 9 ; at 9.35 GHz, the reflection coefficient of the metal structure layer 1 to the electromagnetic wave under the 0°-40° incidence is not 1 and is close to 0, and 0°-40° is defined as the wave transmission angle θ0; the reflection coefficient of the electromagnetic wave under the 60°-80° incidence is close to 1, and 60°-80° can be defined as the reflection angle θr ; as shown in Figure 8 , when 9.35 GHz, θ0=0° electromagnetic wave incidence, the thickness h2 of the air medium layer 1 should be greater than 0, and satisfy h2=6.8, 22.8, 38.8mm…; for other wave-penetrating angles and polarized electromagnetic waves, the corresponding h2 can be calculated by the same method; finally, considering that the transmission coefficients of 0°-40° incidence angles under two polarization modes should satisfy, therefore, the thickness h2 of the air medium layer between the first layer of metal structure layer and the second layer of metal structure layer is selected as 23mm (in this embodiment, rounding off is used.)

[0057] Based on the finite element commercial electromagnetic simulation software ANSYS HFSS2023R1, the wave-penetrating coefficients of the angle selection surface structure in example 1 when TE polarization and TM polarization electromagnetic waves are incident at 0°-80° at 9.35 GHz are simulated and calculated, and the results are shown in Figure 10 ; as shown in Figure 10 , the horizontal axis represents the incidence angle θ of the incident wave, and the vertical axis represents the amplitude of the wave-penetrating coefficient; from the results, it can be known that at the working frequency of 9.35 GHz, the 1dB passband angle of TE polarization electromagnetic wave incidence is 0°-40°; the transition band angle range of the wave-penetrating coefficient from -1dB to -15dB is 40°-50°, and the out-of-band steepness is good; the 1dB passband angle of TM polarization is 0°-37°; the transition band angle range of the wave-penetrating coefficient from -1dB to -15dB is 37°-59°. This structure has the characteristics of wide passband angle, out-of-band steepness and dual polarization angle selection.

[0058] Example 2:

[0059] Referring to Figure 4 and Figure 5 , in this embodiment, four layers of metal structure layers are used, the first layer of metal structure layer, the second layer of metal structure layer and the first layer of air medium layer are combined to form a combined structure C, and the third layer of metal structure layer, the fourth layer of metal structure layer and the third layer of air medium layer are combined to form a combined structure D. The microwave network schematic diagram of this structure can be referred to Figure 7 ; the second layer of air medium layer is characterized by a transmission line with a length of h3; since the combined structure C and the combined structure D are completely the same, the reflection coefficients of the two microwave networks satisfy the condition that the amplitudes are equal

[0060] In this embodiment, the dielectric substrate adopts a square plate with a relative dielectric constant of 2.08, the period (side length) P of the periodic unit is 16mm, and the thickness h1 of the dielectric substrate is 1.6mm; see Figure 3, Jerusalem cross-shaped metal main arm of each main arm length L1 = 10 mm, main arm width W1 = 2 mm; branch arm length L2 = 8 mm, branch arm width W2 = 3 mm; metal via radius r1 = 1 mm, the thickness of the first layer air medium layer and the third layer air medium layer is h2 = 23 mm.

[0061] Based on the finite element commercial electromagnetic simulation software ANSYS HFSS2023R1, the reflection coefficient phase of the combined structure C in the above embodiment under TE polarization and TM polarization electromagnetic wave at 0° incidence is simulated and calculated, and the calculation results can be referred to Figure 11 ; the reflection coefficient amplitude of the combined structure C under TE polarization and TM polarization electromagnetic wave at 0°-80° incidence is simulated and calculated, and the calculation results can be referred to Figure 12 ; 9.35GHz, the reflection coefficient of the metal structure layer 1 to the 0°-40° incident electromagnetic wave is not 1, and is close to 0, and 0°-40° is defined as the wave-transparent angle θ0. The reflection coefficient of the electromagnetic wave incident at 60°-80° is close to 1, which can be defined as 60°-80° as the reflection angle θ r ; as shown in Figure 11 , when θ0=0° electromagnetic wave is incident at 9.35GHz, the thickness h3 of the air medium layer 2 should be greater than 0, and the thickness h3 of the second layer air medium layer should satisfy h3 = 9.07, 25.07, 41.07 mm…; for other wave-transparent angles and polarization conditions, the corresponding h3 can be calculated by the same method; finally, considering that the transmission coefficients at 0°-40° incidence under two polarization modes should satisfy, therefore, h3 = 23 mm is selected.

[0062] Based on the finite element commercial electromagnetic simulation software ANSYS HFSS2023R1, the wave-transparent coefficient of the angle selection surface structure in the above embodiment 2 under TE polarization and TM polarization electromagnetic wave at 9.35GHz at 0°-80° incidence is simulated and calculated, and the results are shown in Figure 13 ; as shown in Figure 13 , the horizontal axis represents the incidence angle θ of the electromagnetic wave, and the vertical axis represents the amplitude of the transmission coefficient; from the results, it can be known that at the working frequency of 9.35GHz, the 1dB passband angle of TE and TM polarization electromagnetic wave incidence is 0°-40°; the wave-transparent coefficient of TE polarization incidence decreases from-1dB to-15dB in the transition band angle range of 40°-50°; the wave-transparent coefficient of TM polarization incidence decreases from-1dB to-15dB in the transition band angle range of 40°-52°. This structure has the characteristics of wide passband angle, steep drop outside the band, and polarization-insensitive.

[0063] The above examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A dual-polarized angular selective surface structure with wide passband angle and out-of-band drop, characterized in that, The angle selection surface structure is composed of a plurality of periodic units connected to each other, and each periodic unit is provided with at least two metal structure layers from top to bottom, and an air medium layer unit is arranged between adjacent metal structure layers. The metal structure layer includes a dielectric substrate, and the upper and lower surfaces of the dielectric substrate are respectively provided with an upper surface metal layer and a lower surface metal layer. The upper surface metal layer and the lower surface metal layer are connected through metal vias arranged in the dielectric substrate. The upper surface metal layer and the lower surface metal layer have the same structure, and each periodic unit includes a plurality of Jerusalem metal sheets distributed in the circumferential direction around the center of the dielectric substrate. The Jerusalem metal sheet is a cross structure including a cross metal main arm and four branch arms perpendicularly arranged at the ends of the cross metal main arm. The innermost branch arms of each Jerusalem metal sheet are connected to each other. The middle hole of the cross metal main arm is the end of the metal via, and the metal via connects the cross metal main arm in the corresponding position on the upper and lower surfaces of the dielectric substrate.

2. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 1, characterized in that, The branch arms of the Jerusalem metal sheet and the edges of the dielectric substrate of the periodic unit form an angle of 45°.

3. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 1, characterized in that, The metal structure layer is provided with two layers, a first layer metal structure layer and a second layer metal structure layer, which are equivalent to microwave network A and microwave network B, and the reflection coefficient of the first layer metal structure layer represents the scattering parameter of microwave network A , The phase is represented as ; The reflection coefficient of the second layer of metal structure layer is characterized as a scattering parameter of microwave network B , The phase is represented as ; At the wave-transparent angle , the reflection coefficient amplitudes of the first layer of metal structure layer and the second layer of metal structure layer satisfy: , the thickness of the air medium layer between the first layer of metal structure layer and the second layer of metal structure layer satisfies , ; wherein, is the wave number of the working frequency; at the reflection angle , the reflection coefficients of the first layer of metal structure layer and the second layer of metal structure layer satisfy = 1.​​​​​ 4. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 3, characterized in that, The specific determination method of the thickness h2 of the air medium layer is as follows: First, determine the structure parameters of the metal structure layer in the angle selection surface structure. Secondly, electromagnetic simulation software was used to simulate and calculate the surface structure with determined structural parameters and angle selection. During the calculation, the amplitude of the reflection coefficient of the first metal structural layer under a preset polarization mode with electromagnetic waves incident at angles between 0° and 80° was simulated. Based on the reflection coefficient values ​​in the simulation results, the wave transmission angle range was determined. The formula was then used... = + ) Calculate the parameters for each transmission angle within the transmission angle range under the preset polarization mode. A series of air medium layer thicknesses corresponding to different values The preset polarization mode is either TE polarization or TM polarization. Finally, the corresponding values ​​for each transmission angle determined under the two different polarization modes were obtained. Then, h2, which simultaneously satisfies the transmission coefficient of electromagnetic wave incident angle under both different polarization modes, is selected as the final determined air medium layer thickness; wherein, the range of electromagnetic wave incident angle is the transmission angle range.

5. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 1 or 3, characterized in that, The metal structure layer is provided with four layers, and the four layers of metal structure layers have the same structure, and the first and second layers of metal structure layers and the third and fourth layers of metal structure layers have the same structure of the first and third layers of air medium layers.

6. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 5, wherein, The combination of the first layer metal structure layer to the second layer metal structure layer is denoted as a combination structure C, the combination structure C is equivalent to a microwave network C, and the reflection coefficient of the combination structure C can be characterized as a scattering parameter of the microwave network C , The phase is denoted as ; the combination of the third layer metal structure layer to the fourth layer metal structure layer is denoted as a combination structure D, the combination structure D is equivalent to a microwave network D, and the reflection coefficient of the combination structure D is characterized as a scattering parameter of the microwave network D , The phase is denoted as ; at the wave-transparent angle , the reflection coefficient amplitudes of the combination structure C and the combination structure D satisfy = | | , and the thickness of the air medium layer therebetween should satisfy = + ), ; wherein is the wave number of the working frequency; at the reflection angle , the reflection coefficients of the combination structure C and the combination structure D satisfy = | |= 1.

7. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 5, wherein, The dielectric substrate is a square plate with a relative dielectric constant of 2.08, the side length P of the periodic unit is 16 mm, and the thickness h1 of the dielectric substrate is 1.6 mm. The length L1 of each main arm of the cross metal main arm in the Jerusalem metal sheet is 10 mm, and the width W1 of the main arm is 2 mm. The length L2 of the branch arm is 8 mm, and the width W2 of the branch arm is 3 mm. The radius r1 of the metal via is 1 mm.

8. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 5, wherein, The thickness of the first air medium layer and the third air medium layer is .

9. The dual-polarized angular selective surface structure with wide passband angle and out-of-band drop according to claim 5, wherein, The thickness of the second layer of air dielectric layer .

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