Dielectric bandpass filter

摘要

To reduce the number of components and enable the mounting work of a filter unit onto a printed substrate without using a metal case, a filter unit of three-state structure with resonators is constructed in which an electrode is formed on an inner peripheral surface of each through-hole and an outer peripheral surface of a dielectric member except for one end face, and connector terminals each composed of a pin and an insert member are inserted into opening portion of the end face of the through-holes to form a dielectric bandpass filter. An enlarged insert portion is formed in the opening portion of each through-hole so as to form a stepped portion between the insert portion and a non-insert portion. The insert member has the same configuration as that of the insert portion and is inserted and fitted in the insert portion without projecting from the end face. At the same time, the movement of the insert member toward the non-insert portion is restricted by the stepped portion. The connector terminals are mounted in a stationary manner in a predetermined position within the through-holes.