Analysis of Curved Frequency Selective Surfaces

This article presents the full-wave analysis of frequency selective surfaces (FSS) embedded in a multilayer spherical supporting structure. The FSS are composed of circular ring elements because of its good polarisation properties and insensitivity of the resonant frequency on the angle of the incident plane wave. In order to analyse very large arrays with many elements, the element-by-element approach is modified and a new algorithm is proposed. In the new approach, for the purposes of calculating the mutual coupling, the array is split into overlapping subarrays that are analysed sequentially. The subarray analysis results are then superimposed to get the reflection and transmission properties of the whole curved FSS. A number of other techniques are also applied in order to speed up the analysis of such a large system.