The microwave dielectric properties of chalcogenide glasses

Abstract

The microwave dielectric properties of the chalcogenide glass ASggTeggGe^g (by atomic percent) were determined, utilizing the trans mission method. The relative permittivity was found to be 15.9 + 0.9 for the 8.0 to 12.4 GHz frequency band. The loss tangent was found to be less than or equal to 0.3 throughout the same frequency band. The error in the relative permittivity measurements was determined to be less than 5%. Samples were prepared from 99.99%.pure arsenic, tellurium, and germa nium. Quartz ampules containing the As^gTe^^Ge^Q were heated to 1000 degrees centigrade for 24 hours and then quenched in liquid nitrogensoaked sand. Test samples were produced by placing the quenched ASg^Teg^Ge^Q in chrome-plated molds, reheating to 600 degrees centigrade, and requenching, using dry ice. The transmission method yielded excellent results for low, medium, or high relative permittivity samples, regardless of sample thickness. The method is based on the comparison of the dominant Transverse Electric fields in a rectangular waveguide with and without a sample being present. The resulting transcendental equation with two unknowns was solved by generating tables based on the substitution of various values of complex relative permittivity, and comparing the corresponding phase shift and amplitude change with the measured values. A unique solution was found by comparing results of samples of different thicknesses.