A Novel Ultra-Wideband Switch-Type Active Frequency Selective Surface for Radome Applications

A switch-type polarization-insensitive active frequency selective surface (FSS) with ultra-wideband (UWB) characteristics is presented in this article. The proposed FSS consists of a periodic array of three metal layers, two dielectric layers and two air space. PIN diodes are arranged on the top and bottom metal layers which are related by two transmission lines. The transmission bandwidth of the active FSS with OFF-state diodes is 7.5-15 GHz with a fractional bandwidth of 67%, and the transmission coefficient of the FSS with ON-state diodes is lower than -14 dB from 2 to 18 GHz. Additionally, the active FSS is polarization-insensitive and angular stable for both TE and TM polarizations. The simulation results show the proposed active FSS is an effective candidate for radar radome applications.