Narrow band pass frequency selective surface

Abstract

A narrow band pass frequency selective surface comprises a metal ring periodic structure, an optical window dielectric layer and a metal mesh periodic structure. The metal ring periodic structure and the metal mesh periodic structure are attached to the surface of the optical window dielectric layer or embedded in the optical window dielectric layer, the cycle of the metal ring periodic structure is P, and the cycle P of the metal ring periodic structure contains side lengths L of metal rings and the shortest distance g between the adjacent metal rings; the cycle of the metal mesh periodic structure is d, and P is an integral multiple of d. The narrow band pass frequency selective surface has the frequency selection characteristic of narrow band pass filtering in the 1-18 GHz radar frequency band while guaranteeing high permeability of visible / infrared windows, and has the advantages that pass band positions are flexible and adjustable, and polarization angles are insensitive and ultrathin. The narrow band pass frequency selective surface is suitable for wide frequency spectrum electromagnetic shielding and filtering in the field of telemetering, medical diagnosis, confidential communication, aerospace aviation and the like.

Description

technical field [0001] The present invention relates to electromagnetic shielding and filtering, in particular to a narrow bandpass frequency selective surface. technical background [0002] With the continuous development and progress of science and technology, the space electromagnetic environment is becoming more and more complex. There are serious electromagnetic interference problems in optical windows in the fields of telemetry and remote sensing, medical diagnosis, secure communication, aerospace equipment, etc., not only from cosmic rays, satellite communications, External electromagnetic wave signals such as TV broadcasts will interfere with the internal working devices of the system, and internal electromagnetic signals will also leak and affect the outside world. Due to the permeability of optical windows to electromagnetic waves, it will become one of the important factors for aircraft exposure in military applications. At the same time, with the continuous brea...

AI Technical Summary

Problems solved by technology

However, this structural design uses a metal structure with a high duty ratio (duty ratio>4) to realize the band-pass filtering function in the microwave frequency band, and does not consider the application in the optical window, that is, it cannot achieve high transparency in the visible to infrared band. limit its scope of application

[0005] 2. Patent 201310385578.9 "High-performance radar / infrared dual-band band-pass frequency selective surface" provides a high-performance radar / infrared dual-band band-pass FSS, including two layers of the same optically transparent FSS and the coupling between the two layers of optically transparent FSS Dielectric, two layers of optically transparent FSS are parallel and symmetrical to the coupling dielectric, which solves the contradiction between optical transmittance and shielding efficiency of single-layer optically transparent FSS in the prior art and the multilayer metal grid array structure cannot realize radar / infrared dual-wave Technical Issues with Bandpass Function

However, the structure design is still relatively complicated, the infrared transmittance is only 77%, and the optical diffraction effect of the double-layer grid structure is more obvious, which seriously affects the actual signal transmission and reception effect of the optical window band

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