A high-frequency selective dual-polarization conversion metasurface based on stripline filter

Abstract

The application discloses a high-frequency selective dual-polarization conversion metasurface based on a stripline filter, comprising a plurality of dual-polarization conversion metasurface units; the dual-polarization conversion metasurface unit comprises a dielectric plate, a resonant unit and a metal via; the dielectric plates are provided with a metal ground layer therebetween, the resonant unit is embedded in the second layer of dielectric plate, the surface of the dielectric plate is provided with an upper metal patch, and the back of the dielectric plate is provided with a lower metal patch; the metal via is connected with the metal patch, the dielectric plate and the resonant unit in sequence; the type of the resonant unit adopts a second-order resonant unit or a third-order resonant unit; for the transmission type dual-polarization conversion metasurface, the filter structure can overcome the problem that the frequency selectivity of the dual-polarization conversion metasurface in the prior art is not high, can realize the dual-polarization conversion function of the incident wave, and has high frequency selectivity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microwave materials, and relates to a high-frequency selective dual-polarization conversion metasurface based on a stripline filter. BACKGROUND

[0002] A metasurface is a two-dimensional electromagnetic metamaterial that can flexibly control the amplitude, phase, polarization and other properties of incident electromagnetic waves at a subwavelength level. Due to the excellent electromagnetic properties of electromagnetic metamaterials, the application research of metasurfaces in the fields of wave-absorbing materials, detection technology, electromagnetic stealth, radar imaging and the like has become a research hotspot at home and abroad.

[0003] Polarization is one of the very important properties of electromagnetic waves, and the polarization of electromagnetic waves refers to the oscillation direction of the electric field in the plane perpendicular to the propagation direction. In a communication system, the selection of electromagnetic wave polarization generally depends on application requirements and propagation environment.

[0004] At present, the control of linear polarization is particularly important in applications such as short-wave communication, frequency modulation broadcasting, radar imaging, wireless communication systems and the like. For example, in a radar imaging system, analyzing the co-polarization and cross-polarization components of incident electromagnetic waves is particularly important for describing the characteristics of a target; for example, in some dynamic communication environment wireless systems, polarization diversity of an antenna can establish more stable and reliable wireless connections.

[0005] In 2018, Peng Xu et al. proposed an ultrathin linear polarization cross-polarization converter in the paper An Ultrathin Cross-Polarization Converter With Near Unity Efficiency for Transmitted Waves (IEEE Transactions on Antennas and Propagation, vol. 66, no. 8, pp. 4370-4373, Aug. 2018), but the frequency selectivity of the polarization converter is very low, and the frequency selectivity at low frequency and high frequency is 4dB / GHz and 11dB / GHz respectively, and the frequency selectivity is not high at the edge of the passband.

[0006] Therefore, the frequency selectivity of some linear polarization converters currently existing is not high, that is, it decreases slowly at the edge of the passband, thereby affecting the anti-interference and electromagnetic compatibility of the system in actual communication systems and deteriorating the performance of the system. Therefore, it is particularly important to design a linear polarization conversion metasurface with high performance. SUMMARY

[0007] In view of the problems in the prior art, the application provides a high-frequency selective transmission type dual-polarization conversion metasurface based on a strip-line filter; for the transmission type dual-polarization conversion metasurface, the proposed filtering structure can overcome the problem of low frequency selectivity of the dual-polarization conversion metasurface in the prior art.

[0008] The application is realized by the following technical solutions:

[0009] A high-frequency selective dual-polarization conversion metasurface based on a strip-line filter comprises a plurality of dual-polarization conversion metasurface units; the dual-polarization conversion metasurface unit comprises a first dielectric plate, a second dielectric plate, a third dielectric plate, a resonant unit and a metal via; a first metal ground layer is arranged between the first dielectric plate and the second dielectric plate, a second metal ground layer is arranged between the second dielectric plate and the third dielectric plate, the resonant unit is embedded in the second dielectric plate, an upper metal patch is arranged on the surface of the first dielectric plate, and a lower metal patch is arranged on the back of the third dielectric plate; the upper metal patch, the first dielectric plate, the resonant unit, the third dielectric plate and the lower metal patch are sequentially and throughly provided with a metal via; and the type of the resonant unit adopts a second-order resonant unit or a third-order resonant unit.

[0010] Preferably, the resonant unit comprises a first resonant unit and a second resonant unit, and the first resonant unit and the second resonant unit are distributed in the second dielectric plate in a central symmetric form.

[0011] Preferably, the resonant unit is a strip-line structure, the second-order resonant unit structure is two sections of strip-line with an electrical length of 90°, and the third-order resonant unit structure comprises a second-order resonant unit and two sections of strip-line of a two-segment one-half wavelength resonator.

[0012] Preferably, a circular hole is arranged on each of the first metal ground layer and the second metal ground layer; and the diameter of the circular hole is greater than the diameter of the metal via.

[0013] Preferably, the upper metal patch and the lower metal patch each comprise a Y-axis metal patch and an X-axis metal patch, and the Y-axis metal patch and the X-axis metal patch are arranged to cross each other; and the Y-axis metal patch and the X-axis metal patch each have a rectangular structure.

[0014] Preferably, the metal via comprises a first metal via, a second metal via, a third metal via and a fourth metal via; the first metal via is arranged on the Y-axis metal patch of the upper metal patch, the second metal via is arranged on the X-axis metal patch of the lower metal patch, the third metal via is arranged on the X-axis metal patch of the upper metal patch, and the fourth metal via is arranged on the Y-axis metal patch of the lower metal patch.

[0015] Preferably, both the first and third dielectric substrates are made of F4B350 dielectric substrates, with a dielectric constant of 3.5 and a loss of 0.003.

[0016] Preferably, the second dielectric substrate 2 is made of a dielectric substrate of model F4B220, with a dielectric constant of 2.2 and a loss of 0.003.

[0017] Preferably, multiple dual-polarization conversion metasurface units are arranged in an array.

[0018] A high-frequency selective dual-polarization conversion metasurface based on a stripline filter exhibits frequency selectivity of 100 dB / GHz and 85 dB / GHz at the low and high frequencies of the passband edge, respectively, when using a second-order resonant unit; and 141 dB / GHz and 130 dB / GHz at the low and high frequencies of the passband edge, respectively, when using a third-order resonant unit.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] This invention provides a high-frequency-selectivity transmissive dual-polarization conversion metasurface based on a stripline filter. The provided dual-polarization conversion metasurface consists of M×N periodically arranged units. By incorporating second-order or third-order resonant units into the filtering structure within the metasurface, it overcomes the problem of low frequency selectivity in existing dual-polarization conversion metasurfaces, achieving dual-polarization conversion of incident waves while maintaining high frequency selectivity. The dual-polarization conversion metasurface units proposed in this invention can all achieve dual-polarization conversion of incident polarized waves, i.e., converting Y-polarized incident electromagnetic waves into transmitted X-polarized electromagnetic waves, and X-polarized incident electromagnetic waves into transmitted Y-polarized electromagnetic waves, with a highly frequency-selective polarization conversion response.

[0021] Furthermore, to prevent short circuits in the metal vias, circular holes are etched on the metal grounding layer, and the diameter of the circular holes is larger than the diameter of the metal vias, ensuring that the metal vias can pass smoothly through the metal grounding layer without short circuits.

[0022] Furthermore, this invention incorporates a simple resonant unit as a planar filter structure into the polarization conversion metasurface, which has a very significant effect on improving frequency selectivity. The high frequency selectivity of the polarization conversion metasurface can improve the anti-interference and electromagnetic compatibility characteristics of the communication system.

[0023] Furthermore, through simulation calculations, the present invention shows that the frequency selectivity of the dual-polarization conversion metasurface unit using a second-order resonant unit at the low and high frequencies of the passband edge is 100 dB / GHz and 85 dB / GHz, respectively; and the frequency selectivity of the dual-polarization conversion metasurface unit using a third-order resonant unit at the low and high frequencies of the passband edge is 141 dB / GHz and 130 dB / GHz, respectively.

[0024] Furthermore, the second-order and third-order resonant units of the present invention can improve the frequency selectivity of the polarization conversion metasurface. Moreover, through simulation results, it can be clearly seen that the frequency selectivity of the third-order resonant unit is better than that of the second-order resonant unit. Therefore, the filter structure can achieve high frequency selectivity, and the method of increasing the order of the stripline filter can further improve the frequency selectivity. Attached Figure Description

[0025] Figure 1 This is a three-dimensional perspective view of the second-order resonant unit structure of Embodiment 1 of the present invention;

[0026] Figure 2 This is a top view of the upper patch structure of Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the first metal ground plane in Embodiment 1 of the present invention;

[0028] Figure 4 This is a top view of the strip structure of Embodiment 1 of the present invention;

[0029] Figure 5 This is a top view of the lower layer patch structure in Embodiment 1 of the present invention;

[0030] Figure 6 This is a three-dimensional schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0031] Figure 7 This is a schematic diagram of the structure of a 10×10 array according to Embodiment 1 of the present invention;

[0032] Figure 8 This is a three-dimensional perspective view of the third-order resonant unit structure of Embodiment 2 of the present invention;

[0033] Figure 9 This is the stripline structure of the third-order resonant unit in Embodiment 2 of the present invention;

[0034] Figure 10 The simulation results are for Embodiments 1 and 2 of the present invention.

[0035] In the figure: First dielectric substrate 1, Second dielectric substrate 2, Third dielectric substrate 3, First metal grounding layer 4, Second metal grounding layer 5, Upper metal patch 6, Strip line 7, Lower metal patch 8, First metal through hole 9, Second metal through hole 10, Third metal through hole 11, Fourth metal through hole 12, Circular hole 13. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0037] The dual-polarization conversion metasurface provided by this invention consists of M×N (M, N≥2) periodically arranged units. Both the proposed second-order and third-order dual-polarization conversion metasurface units can achieve dual-polarization conversion of incident polarized waves, that is, converting Y-polarized incident electromagnetic waves into transmitted X-polarized waves, and X-polarized incident electromagnetic waves into transmitted Y-polarized electromagnetic waves, and the polarization conversion response exhibits high frequency selectivity.

[0038] It includes multiple dual-polarization conversion metasurface units; the multiple dual-polarization conversion metasurface units are arranged in an array; the dual-polarization conversion metasurface units mainly include: a first dielectric substrate 1, a second dielectric substrate 2, a third dielectric substrate 3, a first metal ground layer 4, a second metal ground layer 5, an upper metal patch 6, a stripline 7, a lower metal patch 8, a first metal through hole 9, a second metal through hole 10, a third metal through hole 11, a fourth metal through hole 12, and a circular hole 13.

[0039] The dual-polarization conversion metasurface unit includes a first dielectric substrate 1, a second dielectric substrate 2, a third dielectric substrate 3, a resonant unit, and metal vias. A first metal grounding layer 4 is disposed between the first dielectric substrate 1 and the second dielectric substrate 2, and a second metal grounding layer 5 is disposed between the second dielectric substrate 2 and the third dielectric substrate 3. The resonant unit is embedded in the second dielectric substrate 2. An upper metal patch 6 is disposed on the surface of the first dielectric substrate 1, and a lower metal patch 8 is disposed on the back of the third dielectric substrate 3. The upper metal patch 6, the first dielectric substrate 1, the resonant unit, the third dielectric substrate 3, and the lower metal patch 8 are sequentially connected by metal vias. The metal vias are covered with a conductive metal layer on their sidewalls. The type of the resonant unit is a second-order resonant unit or a third-order resonant unit. The input end of the metal through-hole is connected in sequence to the upper metal patch 6, the first dielectric substrate 1, and the wiring terminal of the resonant unit; the output end of the metal through-hole is connected in sequence to the wiring terminal of the resonant unit, the third dielectric substrate 3, and the lower metal patch 8; the type of the resonant unit is either a second-order resonant unit or a third-order resonant unit.

[0040] The dielectric substrate of this invention uses Rogers, FR4 series and other materials;

[0041] Preferably, according to an embodiment of the present invention, the first dielectric substrate 1 and the third dielectric substrate 3 are both made of F4B350 dielectric material with a thickness of 1 mm, having a dielectric constant of 3.5 and a loss of 0.003. The second dielectric substrate 2 is made of F4B220 dielectric material with a thickness of 1 mm, having a dielectric constant of 2.2 and a loss of 0.003. The first metal ground layer 4 and the second metal ground layer 5 are the ground planes of the upper metal patch 6 and the lower metal patch 8, respectively, and also serve as the ground planes of the stripline. The resonant unit includes a first resonant unit and a second resonant unit, which are distributed in a centrally symmetrical manner within the second dielectric substrate 2.

[0042] Both the first metal grounding layer 4 and the second metal grounding layer 5 are provided with circular holes 13; the diameter of the circular holes 13 is larger than the diameter of the metal through holes.

[0043] Both the upper metal patch 6 and the lower metal patch 8 include a Y-axis metal patch and an X-axis metal patch, which are arranged intersectingly. Both the Y-axis and X-axis metal patches are rectangular. According to an embodiment of the present invention, the upper metal patch 6 is composed of two intersecting rectangular metal patches of the same size. The lower metal patch 8 has the same shape and size as the upper metal patch 6.

[0044] The metal through-holes include a first metal through-hole 9, a second metal through-hole 10, a third metal through-hole 11, and a fourth metal through-hole 12; the first metal through-hole 9 is disposed on the Y-axis metal patch of the upper metal patch 6, the second metal through-hole 10 is disposed on the X-axis metal patch of the lower metal patch 8, the third metal through-hole 11 is disposed on the X-axis metal patch of the upper metal patch 6, and the fourth metal through-hole 12 is disposed on the Y-axis metal patch of the lower metal patch 8.

[0045] According to an embodiment of the present invention, to prevent short circuits in the metal vias, circular holes 13 are etched in the metal ground layer. There are two holes of the same size in the first metal ground layer, and similarly, two holes of the same size are etched in the second metal ground layer.

[0046] According to an embodiment of the present invention, the resonant unit in the middle of the second dielectric substrate 2 is a stripline 7 structure, which comprises two striplines 7 of identical size. The filtering structure of the second-order resonant unit proposed in this invention consists of two striplines 7 with an electrical length of 90°, and the filtering structure of the third-order resonant unit consists of two striplines 7 with an added half-wavelength resonator based on the filtering structure of the second-order resonant unit, enabling current coupling. This stripline plays a very important role in the high-frequency selectivity of the structure.

[0047] According to an embodiment of the present invention, the mechanism for achieving dual-polarization conversion is as follows: a rectangular patch placed along the Y-axis in the upper metal patch can be excited by an incident Y-polarized wave. This patch is connected to one end of one of the middle striplines through a metal via, and the other end of the stripline is connected to a rectangular patch placed along the X-axis in the lower metal patch. This allows the incident Y-polarized electromagnetic wave to be transmitted as an X-polarized electromagnetic wave. Similarly, the rectangular patch placed along the X-axis in the upper patch, the metal via, the other stripline, the metal via, and the rectangular patch placed along the Y-axis in the lower patch can achieve the conversion of the incident X-polarized electromagnetic wave into a Y-polarized electromagnetic wave. Therefore, the second-order and third-order resonant dual-polarization conversion metasurface unit can achieve polarization conversion from Y-polarized incident electromagnetic wave to X-polarized transmitted electromagnetic wave, and from X-polarized incident electromagnetic wave to Y-polarized transmitted electromagnetic wave. Furthermore, the filter structure designed above provides this embodiment with high selectivity.

[0048] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

[0049] The following detailed descriptions are all illustrative of embodiments and are intended to provide a further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention.

[0050] The dual-polarization conversion surface of this invention is fabricated using PCB processing technology, which mainly involves the following steps:

[0051] Material cutting: The substrate material that meets the requirements is cut, ground, planed, and baked according to the engineering design to process it into the substrate size of the substrate to facilitate the production of subsequent processes;

[0052] Lamination: Using chemical principles, an oxide layer is formed on the clean copper surface to serve as a metallic grounding layer. The PP sheets are then fused together under high temperature and pressure, bonding each dielectric substrate to the metallic grounding layer.

[0053] Drilling: Drilling through-holes in accordance with engineering design requirements for interlayer interconnection, conduction, and finished component insertion and installation of PCB.

[0054] Plating copper: A thin layer of copper is deposited on the entire printed circuit board (especially the hole walls) to metallize the circular holes (the holes have copper inside to conduct electricity) so that subsequent in-hole electroplating can be performed, and copper is plated on the hole walls.

[0055] Electroplating: Utilizing electrochemical principles, a certain thickness of metal (copper, tin, nickel, gold) is plated onto the exposed copper surface and inside the holes, achieving reliable interconnection between layers while also providing corrosion resistance, weldability, and wear resistance.

[0056] Alkaline etching: Removes unwanted copper and tin from the circuit board to obtain the desired circuitry, completing the outer layer circuitry fabrication.

[0057] Solder resist: A uniform layer of solder resist ink is formed on a circuit board through screen printing.

[0058] Testing: Use a computer to test for open / short circuits to ensure that the product's electrical connectivity meets the user's design and usage requirements.

[0059] Example 1

[0060] This embodiment is a second-order resonant dual-polarization conversion metasurface unit proposed in this invention.

[0061] like Figures 1-7 The figure shows one embodiment of the present invention. The polarization conversion metasurface unit of this embodiment mainly includes: a first dielectric substrate 1, a second dielectric substrate 2, a third dielectric substrate 3, a first metal ground layer 4, a second metal ground layer 5, an upper metal patch 6, a resonant unit, a lower metal patch 8, a first metal through hole 9, a second metal through hole 10, a third metal through hole 11, and a fourth metal through hole 12.

[0062] refer to Figure 1 The diagram shows a three-dimensional perspective view of the second-order resonant unit. The first dielectric substrate 1 and the third dielectric substrate 3 are both 1mm thick F4B350 dielectrics with a dielectric constant of 3.5 and a loss of 0.003. The second dielectric substrate 2 is 1mm thick F4B220 dielectric with a dielectric constant of 2.2 and a loss of 0.003. The first metal grounding layer 4 and the second metal grounding layer 5 serve as the ground planes for the upper and lower metal patches, respectively, and also act as ground planes for the stripline.

[0063] refer to Figure 2 The upper metal patch 6 consists of two intersecting rectangular metal patches of the same size, placed at an angle. The period of the second-order resonant dual-polarization conversion metasurface unit is p=20.75mm, W1=2.8mm, and L1=17.5mm. The lower metal patch 8 has the same shape and size as the upper metal patch.

[0064] refer to Figure 3To prevent short circuits in the metal vias, holes are etched in the metal grounding layer. There are two identical holes in the first metal grounding layer, with a diameter d2 = 0.9 mm. Similarly, two identical holes are etched in the second metal grounding layer. The diameter of each metal via is d1 = 0.3 mm.

[0065] refer to Figure 4 The second-order resonant unit structure in the second dielectric substrate consists of two striplines 7 with an electrical length of 90°. The two striplines 7 are identical in size, and these striplines play a crucial role in the high-frequency selectivity of the structure. The stripline dimensions of the second-order resonant dual-polarization conversion metasurface unit are: W2 = 0.32 mm, L2 = 1.82 mm, and L3 = 3.38 mm.

[0066] refer to Figure 6 This is a three-dimensional structural diagram of this embodiment, which will now be used to explain the dual-polarization conversion mechanism of this embodiment in detail. A rectangular patch placed along the Y-axis in the upper metal patch can be excited by an incident Y-polarized wave. This patch is connected to one end of one of the middle strip lines through a first metal through-hole 9, and the other end of the strip line is connected to a rectangular patch placed along the X-axis in the lower metal patch 8 through a second metal through-hole 10. This allows the incident Y-polarized electromagnetic wave to be transmitted as an X-polarized electromagnetic wave. Similarly, the rectangular patch placed along the X-axis in the upper metal patch, the third metal through-hole 11, the other strip line, the fourth metal through-hole 12, and the rectangular patch placed along the Y-axis in the lower metal patch can realize the conversion of the incident X-polarized electromagnetic wave into a Y-polarized electromagnetic wave. Therefore, the second-order resonant dual-polarization conversion metasurface unit can realize the polarization conversion from Y-polarized incident electromagnetic waves to X-polarized transmitted electromagnetic waves, and from X-polarized incident electromagnetic waves to Y-polarized transmitted electromagnetic waves. Furthermore, the filter structure designed above gives this embodiment high selectivity.

[0067] refer to Figure 7 This is a schematic diagram of the array of the second-order resonant dual-polarization conversion metasurface unit mentioned above.

[0068] Example 2

[0069] This embodiment presents a third-order resonant dual-polarization conversion metasurface unit proposed in this invention. To further verify the effectiveness of the proposed method for improving frequency selectivity, the third-order resonant unit will be described in detail below.

[0070] refer to Figure 8 The polarization conversion metasurface unit in this embodiment is a third-order resonant dual-polarization conversion metasurface unit. It is based on the second-order unit, but with a change in the stripline structure, the order of the structure is further increased, thereby further improving the frequency selectivity of the dual-polarization conversion metasurface unit.

[0071] The structure of Example 2 is similar to that of Example 1. Except for the size of the upper and lower metal patches and the strip structure, the other parameters are exactly the same as those of Example 1. The same content will not be repeated here.

[0072] In Example 2, the upper patch also consists of two rectangular patches placed crosswise, with the two rectangular patches being the same size and positioned crosswise. The period of the third-order resonant dual-polarization conversion metasurface unit is p=20.75mm, W1=2.8mm, and L1=17.3mm. The shape and size of the lower metal patch are exactly the same as those of the upper metal patch.

[0073] refer to Figure 9 The structure is a third-order resonant unit, consisting of a second-order resonant unit and two striplines 7 with two half-wavelength resonators. Specifically, it adds two striplines 7 with two half-wavelength resonators to the second-order resonant unit, further improving frequency selectivity by increasing the order. The dimensions are: L2 = 2.1 mm, L3 = 2.8 mm, L4 = 4.4 mm, W2 = 0.2 mm, and W3 = 0.3 mm.

[0074] The technical effects of the present invention will be further illustrated below through simulation experiments:

[0075] The frequency response of the resonant unit in the above embodiment was simulated and calculated using the commercial simulation software HFSS_18.0.

[0076] The simulation results of the two embodiments described above are as follows: Figure 10 The figure shows the frequency response of two embodiments in the 4.5-5.5 GHz band. , These represent the co-polarization reflection coefficients of the structure under Y-polarized incident waves and X-polarized incident waves, respectively. , These represent the cross-polarization transmission coefficients of the structure under Y-polarized incident waves and X-polarized incident waves, respectively.

[0077] To further illustrate the high frequency selectivity of this structure, we define the frequency selectivity FS at the passband edge as follows:

[0078]

[0079] in Transmission coefficient 20dB out-of-band attenuation Transmission coefficient 3dB out-of-band attenuation. and Its corresponding frequency.

[0080] Simulation results show that: the second-order resonant unit , The value is greater than -3dB within the frequency band of 4.93-5.06GHz; the third-order resonant unit's , The difference is greater than -3dB within the frequency band of 4.98-5.04GHz. This demonstrates that both embodiments can achieve dual polarization conversion of incident polarized waves within the frequency band, that is, the Y-polarized incident electromagnetic wave is converted into a transmitted X-polarized wave, and the X-polarized incident electromagnetic wave is converted into a transmitted Y-polarized electromagnetic wave.

[0081] Calculations show that the second-order resonant unit exhibits frequency selectivity of 100 dB / GHz at the low-frequency and 85 dB / GHz at the high-frequency end of the passband, while the third-order resonant unit achieves 141 dB / GHz and 130 dB / GHz at the same frequency. Therefore, it can be concluded that this method can improve the frequency selectivity of the polarization-transformation metasurface. Furthermore, simulation results clearly demonstrate that the third-order resonant unit has superior frequency selectivity compared to the second-order resonant unit. Thus, this filter structure can achieve high frequency selectivity, and increasing the order of the stripline filter can further improve the frequency selectivity.

[0082] Finally, it should be noted that the above embodiments do not represent all embodiments of the present invention. For example, if the frequency selectivity of a transmissive dual-polarization conversion surface is improved by increasing the order of the filter, it is also considered within the scope of protection of the present invention. Those skilled in the art can still make equivalent substitutions in implementation and some technical features based on the technical solution of the present invention, but modifications, changes, and equivalent substitutions based on the ideas and principles of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A high frequency selective dual-polarized metasurface based on a stripline filter, characterized in that, The application relates to a dual-polarization conversion metasurface unit, which comprises a first dielectric plate (1), a second dielectric plate (2), a third dielectric plate (3) and a resonant unit; a first metal grounding layer (4) is arranged between the first dielectric plate (1) and the second dielectric plate (2), a second metal grounding layer (5) is arranged between the second dielectric plate (2) and the third dielectric plate (3), the resonant unit is embedded in the second dielectric plate (2), the surface of the first dielectric plate (1) is provided with an upper metal patch (6), the back of the third dielectric plate (3) is provided with a lower metal patch (8); the upper metal patch (6), the first dielectric plate (1), the resonant unit, the third dielectric plate (3) and the lower metal patch (8) are sequentially provided with metal through holes; the type of the resonant unit adopts a second-order resonant unit or a third-order resonant unit. The resonant unit comprises a first resonant unit and a second resonant unit, and the first resonant unit and the second resonant unit are distributed in the second dielectric plate (2) in a central symmetric mode. The resonant unit is in a strip line structure, the second-order resonant unit structure is two sections of strip lines (7) with an electric length of 90 degrees, and the third-order resonant unit structure comprises a second-order resonant unit and two sections of strip lines (7) of two one-half wavelength resonators. The upper metal patch (6) and the lower metal patch (8) each comprise a Y-axis metal patch and an X-axis metal patch, and the Y-axis metal patch and the X-axis metal patch are arranged in a cross mode; the Y-axis metal patch and the X-axis metal patch are each in a rectangular structure. The metal through holes comprise a first metal through hole (9), a second metal through hole (10), a third metal through hole (11) and a fourth metal through hole (12); the first metal through hole (9) is arranged on the Y-axis metal patch of the upper metal patch (6), the second metal through hole (10) is arranged on the X-axis metal patch of the lower metal patch (8), the third metal through hole (11) is arranged on the X-axis metal patch of the upper metal patch (6), and the fourth metal through hole (12) is arranged on the Y-axis metal patch of the lower metal patch (8).

2. The high-frequency selective dual-polarization converting metasurface based on stripline filter according to claim 1, characterized in that, Circular holes (13) are arranged on the first metal grounding layer (4) and the second metal grounding layer (5); the diameter of the circular holes (13) is larger than that of the metal through holes.

3. The high-frequency selective dual-polarization converting metasurface based on stripline filter according to claim 1, characterized in that, The materials of the first dielectric plate (1) and the third dielectric plate (3) are both F4B350 dielectric plates, the dielectric constants are both 3.5, and the losses are both 0.

003.

4. The high-frequency selective dual-polarization converting metasurface based on stripline filter of claim 1, wherein, The material of the second dielectric plate (2) is an F4B220 dielectric plate, the dielectric constant is 2.2, and the loss is 0.

003.

5. The high-frequency selective dual-polarization converting metasurface based on stripline filter according to claim 1, characterized in that, The multiple dual-polarization conversion metasurface units are arranged in an array mode.

6. The high-frequency selective dual-polarization converting metasurface based on stripline filter of claim 1, wherein, The frequency selectivity of the second-order resonant unit of the dual-polarization conversion metasurface unit at low frequency and high frequency at the passband edge is 100 dB / GHz and 85 dB / GHz respectively; the frequency selectivity of the third-order resonant unit of the dual-polarization conversion metasurface unit at low frequency and high frequency at the passband edge is 141 dB / GHz and 130 dB / GHz respectively.

Images