Abstract
—The most important requirements of well designed planar absorbers are compact size or thin layer structure and wideband performance for a specified reflectance level. In this paper, analytical treatment of thin planar absorber structures having two layers is given. The possibility of obtaining wideband performance of such structures using magnetic and electric dispersive materials is examined. Illustrative curves are given for the cases that produce an optimized 20 dbs bandwidth absorber. Optimum frequency dependence of absorber materials that can lead to wideband performance with lowest possible reflectance levels has also been deduced.