Millimeter-Wave Circularly Polarized Vivaldi Antenna Using Simple Single Layer 2D FSS Polarizer

In this paper, a novel wideband polarizer based on a 2D Frequency Selective Surface (FSS), operating in the frequency range of 28 to 32 GHz, is designed and characterized. This polarizer consists of an array of 9 x 9 "T" shaped unit-cells that converts a linearly polarized wave to a circular polarized wave. To demonstrate the principle, the proposed single layer FSS is applied to a linearly polarized Vivaldi antenna operating in the same millimeter-wave frequency band. The simulation results, by placing the proposed polarizer in front of the antenna, show that an axial ratio (AR) smaller than 3 dB is obtained over a wide bandwidth with a gain enhancement, confirming the polarization conversion.