Abstract: Devices are described which incorporate dielectric material with unusually low (and sometimes negative) temperature coefficient of dielectric constant. Such materials make possible the fabrication of microwave devices which remain stable with changing temperature. This is particularly useful for stabilization of frequency in microwave sources. Stabilization results from the incorporation of small amounts of tin in ceramic material containing mostly Ba.sub.2 Ti.sub.9 O.sub.20.

Abstract: A process is described for the preparation of ceramic dielectrics for microwave applications which yield high quality (Q) factors, high dielectric stability and excellent mechanical stability. The procedure is particularly useful where the size of the ceramic dielectric structures is large (average diameter greater than one inch).

Abstract: A ceramic composition and processing procedure is described which is useful in electric and electronic devices such as thermistors. The ceramic composition, which may be described as a semiconducting barium titanate, exhibits a large positive temperature coefficient of resistance. Advantages are ease and convenience of fabrication with lower sintering temperature than conventional processing and use of an air atmosphere instead of nitrogen or oxygen atmospheres. This facilitates batch processing and permits convenient sintering in a continuous kiln.

Abstract: Devices are described which utilize a low loss dielectric material. This dielectric material is unique in that it combines low dielectric loss with a high and temperature-stable dielectric constant. The material is made up of BaO and TiO.sub.2 and corresponds closely in composition to the compound Ba.sub.2 Ti.sub.9 O.sub.20. Devices utilizing this material are useful at a variety of frequencies, but are particularly advantageous in the microwave region above 0.5 GHz.