Double-layer resistive FSS structure for ultra-wideband microwave absorption

This paper presents a double-layer resistive FSS absorber consists of resistive film patches and polyurethane foam. The absorber has ultra-wideband microwave absorption with the characteristic of polarization-independent and incident-angle-insensitive. The equivalent circuit theory is employed to analysis the working mechanism of the absorber. It is shown through the simulation that the fractional bandwidth of 142.8% is realized for the reflectivity below -10dB under the normal incidence. Furthermore, the total thickness of the proposed absorber is only 0.11 at the low operating frequency.