A Low-Profile Wideband Absorber Using Capacitive Surface

In this paper, a single-layer wideband absorber with wide angular coverage is presented. The resistive surface is realized by a periodic array of I-shaped capacitive patterns with chip resistors. By introducing the capacitive patterns, the distance between metal ground and resistive surface with air space is reduced to 1/5 λ @10 GHz. A 10-dB absorption bandwidth from 5.5 GHz to 14.5 GHz has been observed in simulation under normal incidence of TE polarization. This structure also exhibits an angular stability up to 30° with a wide absorption band of at least 90% absorptivity from 4.8 GHz to 14.5 GHz. The fabricated design shows good agreement with the simulation.