Transmission performance analysis of circular polarisation frequency selective surface and fast accurate optimisation based on equivalent circuit

Abstract

In this study, a promising application of frequency selective surface (FSS) operating in circular polarisation is analysed and designed. Both magnitude and phase consistencies between transverse electric (TE) and transverse magnetic (TM) waves are emphasised, especially transmission phase agreement. Equivalent circuit model (ECM) provides a deep physical insight into phase discrepancy between TE and TM waves. The effects of geometrical parameters of FSS on magnitude and phase consistencies are also investigated by ECM. Additionally, an optimisation process is utilised to obtain desired frequency responses for multi-layer FSS design. This process involves iterative correction and update of coarse circuit model on the basis of a few accurate full wave simulations. Moreover, a dual-layer square slot FSS is efficiently designed using this optimisation method. Finally, a prototype of the optimised dual-layer square slot FSS is fabricated and tested to validate the simulated results.