Abstract: A generalized dielectric resonator filter is disclosed for the realization of the most general transfer function characteristics of band-pass filters using cylindrical dielectric resonator discs in a microstrip transmission line configuration. The dielectric resonator filter of the invention has electrical properties comparable to conventional waveguide filters, but has a much smaller volume and mass, and is thus very attractive for use in the construction of input multiplexers of communications satellite transponders.

Abstract: A device for a resonant microwave cavity which includes a tuning plunger assembly to make the resonant frequency less temperature sensitive. The frequency response of a cavity filter, determined by its resonant frequency, primarily depends on the dimensions of the filter cavity. Since cavity dimensions will vary with changes in ambient temperature, some form of compensation is necessary to stabilize the frequency response. The tuning plunger assembly is comprised of a sandwich of materials having substantially different coefficients of expansion. One of the materials, a potting compound with a high coefficient of thermal expansion, acts as an operator to vary the configuration of the plunger assembly in order to maintain the resonant frequency of the cavity substantially fixed.