Microwave absorber using single-layer FSS with wideband operation above the x-band

This work presents the design of a planar microwave absorber based on frequency selective surface (FSS). The absorber provides wide absorption bandwidth above the X-band. The proposed design consists of a single-layer FSS over a ground plane. The unit cell of the FSS is a miniaturized form of a rectangular loop structure made of perfect electric conductor (PEC). For absorption, lumped resistive elements are inserted on the four sides of the loop. The designed is modeled and analyzed using a commercial full-wave package and the absorption mechanism is explained by an equivalent circuit. Through simulations, the absorption bandwidth obtained for the proposed design is between 14.2–30.3 GHz. The angular stability of the proposed design is also analyzed and it is found be stable for 45
^°
and 30
^°
in TE and TM modes, respectively.