Metamaterial-inspired wideband absorber adopting biconical structure

A metamaterial-inspired absorber adopting a biconical structure is proposed at X-band. A unit cell of the absorber is designed and simulated. The side length of the unit cell is 6.5 mm. The absorber consists of biconical structures and conducting plane separated by FR-4(εr = 4.4-j0.02) substrate with 3.3 mm height. Parameter studies demonstrate that the absorber is polarization-insensitive and offers absorption rate over 90 % from 6.2 GHz to 12.3 GHz.