Fast Design of Ultra-Wideband Absorbers Based on Equivalent Circuit Model

A fast method is presented for designing ultra-wideband absorbers composed of resistive surfaces (RSs), substrates and metallic plate. A general effective permittivity for RSs printed on stratified dielectrics under considering metallic plate is derived to obtain the closed-form relationships between resistance, capacitance and absorber parameters. An equivalent circuit (EC) is developed for absorbers to combine with genetic algorithm to quickly achieve an optimal value of lumped elements, thereby calculating absorber parameters. Utilizing the proposed approach, an absorber within 0.64-41.7 GHz with reflection loss lower than -10 dB is obtained efficiently. The close match between the EC model and full-wave simulation results shows accuracy of the proposed approach. To further verify the proposed method, a 1.16-19.2 GHz absorber was designed and manufactured, and the measurements agreed well with the EC and full-wave simulations.