A large-angle broadband frequency-selective surface

Abstract

The invention provides a large-angle broadband frequency selective surface, which belongs to the technical field of electromagnetic wave frequency selective surface, and includes a first dielectric substrate, a first metal structure array layer, a second dielectric substrate, and a second metal structure stacked in sequence from bottom to top The array layer, the third dielectric substrate, the third metal structure array layer and the fourth dielectric substrate; the first metal structure array layer, the second metal structure array layer and the third metal structure array layer are all formed by periodic arrangement of discrete metal patches to make. The present invention obtains a broadband low-frequency transmission high-frequency reflective frequency selective surface through the coupling of multi-layer metal arrays; on the one hand, it solves the problem of excessive in-band insertion loss when incident at a large angle in the existing frequency selective surface technology; On the other hand, the occurrence of high-frequency grating lobes is suppressed, thereby solving the problem that the high-frequency grating lobes are rapidly enhanced and rapidly moved to low frequencies due to an excessively large incident angle, which affects the normal operation of the frequency selective surface.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic wave frequency selective surfaces, and in particular relates to a large-angle broadband frequency selective surface. Background technique [0002] The frequency selective surface is a two-dimensional periodic structure composed of periodically arranged patch units or slot units. It exhibits frequency-selective filtering characteristics for the propagation of electromagnetic waves, that is, the selection characteristics change with frequency. For certain frequency bands The incident electromagnetic waves in the frequency band can all pass through, while the electromagnetic waves in other frequency bands can be completely reflected. Therefore, the frequency selective surface is also called the space electromagnetic filter, which is commonly used in the fields of hybrid radome stealth, multi-frequency antenna sub-reflector design, electromagnetic compatibility and electromagnetic shielding. ...

AI Technical Summary

Problems solved by technology

[0004] However, for the existing band-pass frequency selective surface, for electromagnetic waves incident at a large angle, the insertion loss of the pass-band is large, and the suppression performance is deteriorated due to the appearance of grating lobes outside the band.

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