Frequency Selective Surface with two Notch Frequencies and Good Incidence Angle Stability for Screening Applications

A two-layer frequency selective surface (ESS) is proposed, which exhibits a highly stable response to incidence up to 45°. The structure consists of a square ring and a fan-like shape resonator. The fan-like shape, positioned on the opposite face of the FR4 supporting dielectric with respect to the square resonator, is rotated by 45° with respect to the symmetry axis of the unit cell. A parametric analysis concerning the frequency response in function of geometrical parameters is reported. The structure exhibits a band-stop response with two notches, but can be tailored to achieve a wideband behavior.