Abstract

Low-loss dielectric powders have been used as the core material of dielectric waveguides in the microwave and millimeter wave regions. Both flexible guides and planar circuits analogous to fiber and integrated optical components have been realized. Transmission losses <10 dB/m and ring resonator Qs of 2000 are obtained at 94 GHz. Bending losses were found to be insignificant for radii of curvature greater than a few centimeters. Directional couplers with fixed and variable coupling were investigated. Barium tetratitanate, nickel aluminum titanate, and magnesium calcium titanate were among the lowest-loss powders studied, exhibiting effective dielectric constants of 3.5-6 in packed powder form. Teflon was used as the cladding material for flexible waveguides, and Teflon, polypropylene, and polystyrene were used as rigid substrates for the planar dielectric channel waveguides.

© 1986 Optical Society of America