Abstract: In accordance with principles of the present invention, a two or more pole dielectric resonator circuit is provided with resonators that are elliptical in cross section orthogonal to the longitudinal axis. The resonators are mounted so that they are rotatable about their longitudinal axes, such that the straight line distance between two adjacent resonators measured in a straight line between orthogonal to and intersecting the longitudinal axes of the two resonators is a function of the orientation of the resonators about their longitudinal axes. The resonators can be oriented about their longitudinal axes in any orientation to adjust their spacing, which is directly proportional to their coupling magnitude, which, in turn, is proportional to the bandwidth of the circuit.

Abstract: In order to permit electronic tuning of the frequency of a circuit including dielectric resonators, such as a dielectric resonator filter, tuning plates are employed adjacent the individual dielectric resonators. The tuning plates comprises two separate conductive portions and an electronically tunable element electrically coupled therebetween. The electronically tunable element can be any electronic component that will permit changing the capacitance between the two separate conductive portions of the tuning plates by altering the current or voltage supplied to the electronically tunable element. Such components include virtually any two or three terminal semiconductor device. However, preferable devices include varactor diodes and PIN diodes.