A low-profile third-order frequency selective-surface with ultra-wideband response

By combining the non-resonant element and the resonant element, a low-profile, third-order FSS is proposed for ultra-wideband operations. The FSS is composed of three periodic metallic array, separated by two same electrically thin dielectric layers. The design principle is discussed and a design example is given to demonstrate its validity. Simulation results show that a third-order frequency response with a bandwidth of 82.5% can be obtained. The FSS example has a thickness of λ/12 and a small size of λ/8 for the unit cell, without any polarization limitation, both for TE and TM incidence.