A transmission polarizer based on width-modulated lines and slots

In this paper a novel printed Frequency Selective Surface (FSS) transmission polarizer is presented. A width-modulated microstrip unit cell is used as the reference element, loaded by a capacitive tuning slot, to achieve the desired axial ratio (AR) performance for the transmitted electromagnetic wave. The dimensions of the unit cell are λ0/2×λ0/2 at 30 GHz. This polarizer provides an axial ratio of 0.99 at the resonance and a cross polarization lower than -20 dB in a more than 5% bandwidth. Theoretical analysis and results of numerical investigations related to the new structure are presented