GA optimized ultra-thin tunable EBG AMC surfaces

This paper investigates a new and novel design approach for creating a tunable electromagnetic bandgap (EBG) surface optimized via a genetic algorithm (GA) for use as an artificial magnetic conductor (AMC). The EBG geometry consists of a frequency selective surface (FSS) on top of a thin dielectric substrate with a PEC backing. The GA is used to evolve the geometry of the FSS and choose the placement of a reactive tunable lumped element. Using this technique a tunable EBG ground plane with a unit cell size smaller than conventional "mushroom" or square patch EBGs can be attained. The GA optimized tunable EBG also has a larger bandwidth and a better ability to suppress upper resonances when compared with conventional tunable EBGs