A low profile retrodirective frequency selective surface for radar earth observation

This paper presents the design of a low profile retrodirective surface composed of a frequency selective surface (FSS). The principle of operation of re-radiation and scattering from the array surface is outlined. A full-wave analysis of individual FSS unit cells and the assembled reflect array is performed to better understand and design the reflector. A commensurate array of unit cells with progressive phase shift is realised using non-identical dimension dual resonant circular loop FSSs. A prototype reflect array was manufactured and the monostatic backscattered field measured in horizontal and vertical polarisation. Comparative measurements on similar sized flat plate and dihedral reflector surfaces were made that demonstrate the reflect array performance.