Tunable Radar Absorber Using Resistive Frequency-Selective Surface and Plasma

This paper presents a wideband and tunable absorber structure by using resistive frequency-selective surface (FSS) and plasma. The resistive FSS layer located on the top side is constructed by low-conductivity square loops. The solid metal ground is located on the bottom side. The plasma layer is between the FSS and metal ground and its dispersive characteristics are represented by the Drude model. Numerical results show that the absorber can absorb 90% of the incident energy at normal incidence in a bandwidth of nearly 10 GHz, and the absorbing band is tunable by changing the plasma frequency.