A 670GHz Non-Resonant Metamaterial Polarization Converter

A low loss 670GHz non-resonant ultra-thin substrate metamaterial circular polarization converter is introduced. The designed polarization converter is a triple layer structure, we adopt
$10\mu\mathrm{m}$
ultra-thin polyimide substrate and quarter wavelength air impedance matching layer to lower its transmission loss. Two-dimensional birefringence metamaterial combined with ultra-thin substrate effectively solve defects of traditional polarizers. It can achieve high-quality circular conversion, and at the same time it can efficiently lower insertion loss and increase bandwidth. The simulation results suggest that between 640GHz-700GHz, insertion loss is less than 1.5dB, axial ratio is less than 3dB, and working bandwidth can reach 8.9%.