Design and Analysis of Polarization-Insensitive Broadband Microwave Absorber for Perfect Absorption

A simple design configuration of a broadband polarization-insensitive double-layered microwave absorber is presented here. The proposed absorber is designed using indium tin oxide (ITO) based on thin resistive film. The novelty of structure is to achieve large absorption bandwidth with more than 99% absorption. The proposed structure is modeled for 20 dB absorption bandwidth at normal incidence from 6.3 GHz to 14.2 GHz spanning over C-band, X-band, and Ku-band. Under oblique incidence the proposed structure is stable up to 60. for TE polarization and 45 degrees for TM polarization. To understand the operating principle of absorption of the proposed structure, an equivalent circuit is derived, and surface current distribution is also studied. A fabricated sample is measured, which validates our simulation.