Integral dielectric filter

Abstract

An integral type dielectric filter is disclosed, in which the insertion loss is minimized, and the damping characteristics desired by the user are satisfied. The dielectric filter includes a dielectric block having first and second faces facing toward each other and having a plurality of side faces. A ground electrode is coated on the entire faces of the dielectric block except the first face. A plurality of through holes pass through the first and second faces, with their surfaces being coated with a conductive material. Input and output electrodes are formed on a face of the dielectric block insulatingly from the ground electrode, for forming an electromagnetic coupling with internal electrodes of the plurality of the through holes. At least one metallic coupling region is formed between the input and output electrodes and between the through holes of the first face insulatingly from the ground electrode and from the input and output electrodes to form a capacitive coupling between the input and output electrodes and the through holes. Thus the insertion loss can be decreased compared with the conventional techniques, while improving the damping rate. Further, at least a non-metallic coupling region is formed to realize an inductive coupling, and thus the damping characteristics can be improved at the high frequency side.