Design of Wideband Energy Selective Surface to Defend against High-power Signals

Recently, there is a need for energy selective surface (ESS) using an active frequency selective surface (FSS) to protect communication systems from high-power electromagnetic waves. The ESS structure has a low insertion loss in the operating frequency band according to the ON/OFF characteristics of the switching element, but when strong electromagnetic waves are incident from the outside, the switching element operates to block the operating frequency. In this paper, we designed a unit structure of an ESS structure that selectively passes the 3.5 GHz band in the case of a low-power signal using a PIN diode, and blocks broadband signals above about 10 GHz in the case of a high-power signal. The designed unit structure has stable characteristics up to an incidence angle of 40°.