A Wideband Compact Polarization-Insensitive Absorber using Modified Resistive Jerusalem Cross FSS

This paper proposes a Frequency Selective Surface (FSS) based Circuit Analog Absorber (CAA) using an array of modified, resistor loaded, Jerusalem cross geometry. The absorber consists of two FR4 dielectric layers separated by an air spacer. The top layer supports the FSS while the bottom layer supports the ground plane. The proposed absorber provides minimum 10 dB reflection reduction of the incoming electromagnetic wave starting from 2.167 GHz to 6.647 GHz, resulting in a fractional bandwidth of 101.657%. The overall footprint of the absorber is quite low. The unit cell size of the proposed design is 0.137 lambda x 0.137 lambda with thickness of 0.081 lambda (lambda being the wavelength corresponding to lower cut-off frequency of the absorption band). Being four fold symmetric geometry, the absorber is insensitive to incident polarization and shows stable response up to 30 degree angle of incidence. It is observed and additional Jerusalem cross at a rotated angle along with a slight modification in the form of a circular aperture at the center of the FSS improves overall absorption.