Temperature compensation apparatus for a resonant microwave cavity

摘要

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.