Tri-Band Band-Stop Frequency Selective Surface using Tortuous Jerusalem Cross with Angularly Stable Response

A tri-band band-stop spatial filter is designed to block the propagation of 900, 1800 and 2400 MHz using two-layer frequency selective surface. One side of unitcell consist of Jerusalem cross element with tortuous main arm and the other side has two co-centered Jerusalem cross elements. Using the tortuous approach smaller unit cell is designed with dimensions of 0.078λ0 X 0.078λ0, where λ0 is the wavelength of lowest resonant frequency in free space. The designed FSS exhibits stable response until 80° of incidence angle for TE and TM polarization.