Reconfigurable conformal slot arrays on artificial substrates

Multilayer frequency selective surfaces (FSS) are needed for optimizing the performance of a broadband antenna. In this paper, we examine various designs of such layered periodic surfaces that can be used to enhance the performance of broadband reconfigurable arrays. Of particular interest is the development of frequency selective volumes which reflect, with pre-specified phase and amplitude of the reflection coefficient, over a broad set of frequencies. Previous emphasis on FSS has been on reflectivity performance, but in this application, the phase response is of more importance. Designing FSS subject to phase requirements is seen to involve some compromise in the reflection coefficient magnitude. A key aspect of the paper is the development of suitable criteria for FSS designs such that conformal antennas can be reconfigured to deliver broad bandwidths. A goal is to also design very thin FSS to serve as artificial substrates for reconfigurable slot arrays.