Design and development of polarizers for millimeter and submillimeter waves using solid anisotropic medium

We have designed and developed polarizers (or polarization converter, λ/4 phase shifter) using solid anisotropic medium of sapphire for millimeter and submillimeter waverange. Prototype polarizers made of sapphire was fabricated for 90 GHz band. The diameter and the thickness of the polarizers are 50mm and 2.8mm, respectively. Characteristics of this prototype polarizer have been measured. A simple and preliminary estimation of the insertion loss and the quantity of the phase shift at present is 0.4dB and 70°, respectively. These results show that polarizers using solid anistropic medium of sapphire are applicable for millimeter and submillimeter waverange.