Miniaturization techniques of microwave components for mobile communications systems - using low loss dielectrics

The high dielectric constant ceramics with extremely low loss is playing the important role in the field of microwave communication systems; as a key material of the temperature stable high Q resonators and filters for the satellite transponder, satellite broadcasting receiver and many other microwave communication equipment; as a key material for the component miniaturization program of cellular radio system both for the base stations and terminals, such as dielectric resonators, multilayer substrates for MCM, antenna element and others. In this report the history and recent topics of the low loss and temperature stable dielectric ceramics with respect to the composition and its characteristics, the basis for a design of the resonator and filter, and an application will be reviewed. The explanation of the recent progress of the multilayer filter modules and SAW devices are also described.