Dielectric filter having non-conductive adjusting regions

Abstract

A dielectric filter with integral electromagnetic shielding comprises a dielectric block having an outer surface including first and second end surfaces and a side surface extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric block and providing integral electromagnetic shielding of the dielectric filter; at least one hole extending through the dielectric body between the first and second end surfaces, having a respective inner surface with a substantially constant cross-sectional shape; a respective pair of internal conductors provided in the at least one hole and conductively connected to the external conductor at respective ends of the hole, a respective non-conductive portion in the hole being spaced from both ends and thereby separating the pair of internal conductors and defining a respective capacitance between the pair of internal conductors, a surface of the respective non-conductive portion being substantially flush with the rest of the inner surface of the hole; and signal input and output electrodes provided on the outer surface of the dielectric body and electrically isolated from the external conductor. Conductive and possibly dielectric material is removed from an end surface of the dielectric block to adjust the resonance frequency and/or the coupling degree of the dielectric filter.