Dual- and triple-passband coupled-complementary FSSs based on the four-arms star geometry

Abstract

The authors propose a system of closely coupled-complementary frequency-selective surfaces (FSSs) based on the four-arms star geometry with dual- and triple-passbands responses for 5G applications. Four complementary structure configurations are presented, and depending on the chosen configuration, the structure can create two or three transmission bands in one or both polarisations of the electromagnetic waves. The designed FSSs are compact and have stable behaviour at different incident angles. The complementary FSS passes signals around 2.6 and 6.2 GHz, and a structural offset allows the transmission at a third frequency (4.2 GHz). To validate the proposed designs, four prototypes are fabricated and measured. Numerical and experimental characterisations are in good agreement.