Combining FSS and EBG Surfaces for High-Efficiency Transmission and Low-Scattering Properties

In this communication, we propose a method to achieve high-efficiency transmission and wideband scattering reduction at two distinctive frequency bands by combining frequency-selective surface (FSS) and electromagnetic bandgap (EBG) surface. Such FSS-EBG surface is composed of two-layered metallic patterns. The bottom FSS layer works as a filter for allowing in-band signal to pass and reflecting out-of-band signal, while the top EBG layer adopts 0 and $\pi $ reflection phase cells with a chessboard distribution to reduce the backward scattering wave. As a proof-of-concept demonstration, the planar and cylindrical surfaces are, respectively, designed to verify such two functionalities. Our FSS-EBG surface can make the antenna signal transmit at S-band with small insertion loss and simultaneously provide wideband low-scattering property at X–Ku band, which is suitable to be used as the stealth antenna radome. In addition, the possibility of integrating polarization conversion function into the passing band is numerically demonstrated.