CN-122026115-A - Low-pass high-resistance frequency selective surface structure with cascade connection of three-dimensional slot line and two-dimensional frequency selective surface

Abstract

The invention discloses a low-pass high-resistance frequency selective surface structure with a three-dimensional slot line and a two-dimensional frequency selective surface in cascade connection, which belongs to the technical field of artificial electromagnetic structures and microwaves, wherein the surface comprises a three-dimensional dual-polarized slot line module and a two-dimensional band-resistance frequency selective surface module which are arranged in cascade connection, an adjustable interval space is reserved between the three-dimensional dual-polarized slot line module and the two-dimensional band-resistance frequency selective surface module, and the three-dimensional module consists of a medium substrate subjected to orthogonal cuttage and a printed slot line structure and realizes low-frequency transmission and high-frequency cutoff; the two-dimensional module is composed of periodic annular metal units, high-frequency secondary suppression is achieved, and the interval space is used for regulating and controlling electromagnetic coupling and suppressing high-order mode resonance. The invention solves the problems of thick structure, unstable stop band and poor angle adaptability of the prior art, has the advantages of light and thin structure, stable stop band performance, good angle adaptability and easy processing, is simple to process and controllable in cost, and is suitable for integrated scenes such as radar radomes, electromagnetic shielding and the like.

Inventors

• KONG LINGQI
• SHEN ZHONGXIANG
• LOU TIAN

Assignees

• 北京理工大学长三角研究院(嘉兴)

Dates

Publication Date

20260512

Application Date

20260317

Claims (5)

1. 1. The low-pass high-resistance frequency selective surface structure is characterized by comprising a three-dimensional dual-polarized slot line module and a two-dimensional band-resistance frequency selective surface module which are arranged in cascade along the propagation direction of electromagnetic waves; The three-dimensional dual-polarized slot line module consists of a first medium substrate, a second medium substrate, a first slot line structure and a second slot line structure, wherein the first slot line structure is printed on the surface of the first medium substrate, the second slot line structure is printed on the surface of the second medium substrate, the first medium substrate and the second medium substrate are in space orthogonal cutting arrangement to form a three-dimensional periodic array, and the first slot line structure and a through slot line of the second slot line structure are in orthogonal correspondence to jointly realize low-frequency electromagnetic wave transmission and high-frequency electromagnetic wave cutoff; The two-dimensional band-stop frequency selective surface module consists of a third dielectric substrate and metal units, wherein the metal units are printed on the surface of the third dielectric substrate in a periodic array form and are used for secondarily suppressing high-frequency electromagnetic waves and widening the stop band range; and an adjustable interval space is reserved between the three-dimensional dual-polarized slot line module and the two-dimensional band-stop frequency selection surface module and is used for regulating and controlling electromagnetic coupling strength between the three-dimensional dual-polarized slot line module and the two-dimensional band-stop frequency selection surface module and inhibiting higher-order mode resonance in a stop band.
2. 2. The low-pass high-resistance frequency selective surface structure of cascade connection of three-dimensional slot lines and two-dimensional frequency selective surface according to claim 1, wherein the first slot line structure and the second slot line structure are both metal patch structures, the extending direction of a through slot line arranged on each metal patch is consistent with the length direction of a corresponding dielectric substrate, and the two slot lines are orthogonal in space by 90 degrees.
3. 3. The low-pass high-resistance frequency selective surface structure of the cascade connection of the three-dimensional slot line and the two-dimensional frequency selective surface according to claim 1, wherein the cutting positions of the first dielectric substrate and the second dielectric substrate are positioned at the midpoints of the respective length directions, and the longitudinal extension lengths of the first dielectric substrate and the second dielectric substrate are consistent.
4. 4. The low-pass high-resistance frequency selective surface structure of the cascade connection of the three-dimensional slot line and the two-dimensional frequency selective surface according to claim 1, wherein the metal units are annular metal patches which are arranged in a periodic array, and the period of the annular array is matched with the unit period of the three-dimensional dual-polarized slot line module.
5. 5. The low-pass high-resistance frequency selective surface structure of the cascade connection of the three-dimensional slot line and the two-dimensional frequency selective surface according to claim 1, wherein the first dielectric substrate, the second dielectric substrate and the third dielectric substrate are made of FR-4 dielectric materials, the thickness is 0.18-0.22mm, the dielectric constant is 4.2-4.4, and the loss tangent is less than or equal to 0.025.

Description

Low-pass high-resistance frequency selective surface structure with cascade connection of three-dimensional slot line and two-dimensional frequency selective surface Technical Field The invention relates to the technical field of artificial electromagnetic structures and microwaves, in particular to a low-pass high-resistance frequency selective surface structure with a three-dimensional slot line and a two-dimensional frequency selective surface cascaded. Background The Frequency Selective Surface (FSS) is used as an artificial electromagnetic structure with spatial frequency filtering characteristics, selective transmission or reflection of electromagnetic waves with different frequencies is realized through periodically arranged metal or slotting units, and the artificial electromagnetic structure has irreplaceable functions in the fields of electromagnetic compatibility, stealth technology, antenna system integration and the like. The low-pass high-resistance FSS can keep low-loss transmission in a low frequency band, and meanwhile, the high-pass high-resistance FSS can realize strong broadband suppression on high-frequency interference signals, so that the FSS becomes a core component for guaranteeing low-frequency working equipment from high-frequency threat. The design thought of the existing low-pass high-resistance FSS is concentrated on a two-dimensional multilayer cascade structure, and the filtering order is improved by superposing a plurality of band-stop FSS units or adding a medium isolation layer, so that the stop band is widened and the inhibition capability is enhanced. The design has three core defects, namely, the engineering application is severely restricted by the fact that a large number of metal layers and dielectric layers are required to be overlapped by a multi-layer two-dimensional structure, so that the overall thickness is larger (the thickness of the conventional typical design is over 20 mm), the integrated requirement of equipment miniaturization and low profile cannot be met, secondly, interlayer electromagnetic coupling is enhanced along with the increase of the layers, gao Cimo resonance is easily excited in a high-frequency stop band to form parasitic transmission peaks, the inhibition depth is reduced to below-10 dB, high-frequency interference cannot be effectively isolated, thirdly, the angle stability is poor, when the incident electromagnetic wave angle exceeds 30 degrees, the passband drift exceeds 0.5GHz, the stop band edge inhibition performance is obviously degraded, and the application scene under the complex electromagnetic environment is difficult to adapt. In order to solve the problems, partial researches try to introduce the optimization performance of a three-dimensional structure, but the existing three-dimensional FSS adopts a three-dimensional metal frame structure, has high processing complexity and high cost, and still does not effectively coordinate the contradiction between 'low profile' and 'wide stop band and high suppression'. Therefore, developing a low-pass high-resistance FSS with a light and thin structure, stable stop band performance, good angle adaptability and easy processing becomes a technical bottleneck to be broken through in the field. Disclosure of Invention The invention aims to solve the problems that the thickness of the existing low-pass high-resistance frequency selective surface structure is large, high-order mode resonance is easy to generate in a stop band and the angle stability is insufficient, and provides a low-pass high-resistance frequency selective surface structure with a three-dimensional slot line and a two-dimensional frequency selective surface in cascade connection. In order to achieve the above purpose, the invention adopts the following technical scheme: The low-pass high-resistance frequency selective surface structure is characterized by comprising a three-dimensional dual-polarized slot line module and a two-dimensional band-resistance frequency selective surface module which are arranged in cascade along the propagation direction of electromagnetic waves; The three-dimensional dual-polarized slot line module consists of a first medium substrate, a second medium substrate, a first slot line structure and a second slot line structure, wherein the first slot line structure is printed on the surface of the first medium substrate, the second slot line structure is printed on the surface of the second medium substrate, the first medium substrate and the second medium substrate are in space orthogonal cutting arrangement to form a three-dimensional periodic array, and the first slot line structure and a through slot line of the second slot line structure are in orthogonal correspondence to jointly realize low-frequency electromagnetic wave transmission and high-frequency electromagnetic wave cutoff; The two-dimensional band-stop frequency selective surface module consists of a third dielectric substrate and met