A Miniaturized Polarization Insensitive Frequency Selective Surface at Ka-band

A wideband miniaturized frequency selective surface (FSS) is proposed at Ka-band. Passband FSSs have largely been studied in recent years however, still higher periodicity, high profile (due to the thicker substrate) and less bandwidth are the most common issues. In this paper, we investigate a novel miniaturized FSS consisting of two metallic layers, separated by a thin dielectric substrate that works as a spatial version of a single passband microwave filter. Patch layer is slotted to increase the capacitance whereas the ground layer has a cross loop aperture for better coupling. Numerical simulations demonstrate that proposed design exhibits a passband resonating at 28.7 GHz with 3dB bandwidth of 8.19GHz from 26.11 to 34.3GHz at normal incidence angle. Since the geometry is symmetric with minuscule array size, proposed FSS structure shows stability for both polarizations and with higher incidence angles (up to 30°).