Design and analysis of dual-band FSS based on equivalent circuit

A method of designing bandpass frequency select surface (FSS) has been proposed based on series and parallel equivalent circuit thought in this article. The novel dual-band equivalent circuits are designed. The equivalent admittances were extracted, and resonance frequency was calculated. The dual-band properties of circuit were verified, which lays foundation for the designing of FSS structure. The FSS unit designed in this paper adapts single-layer thin substrate, and it has simple structure, is easy to implement. The thickness of dual-band is 0.017 wavelength. The angle stability and polarization stability of FSS are improved by utilizing miniaturization ideas and adding symmetrical structures. The dual-band FSS consists of two inner and outer loops nested. The inner ring is the Jerusalem structure, and the outer ring is folded structure, both can be independently adjustable resonance frequency. It can realize stable resonance at center frequencies under oblique incidence of 0 degrees to 60 degrees for both TE and TM polarization. For verifying filtering properties of FSS units, the prototypes are fabricated and measured. The results calculated by full-wave, equivalent circuit method (ECM) and measurement are in good agreement.

Automated summary

This article proposes a method of designing bandpass frequency select surface (FSS) based on series and parallel equivalent circuit thought. Novel dual-band equivalent circuits are designed, and the equivalent admittances and resonance frequency are extracted and calculated. The dual-band properties of the circuit are verified, laying the foundation for the designing of FSS structure. The prototypes fabricated and measured show good agreement with the results calculated by full-wave and equivalent circuit method (ECM).