DIELECTRIC FILTER, DIELECTRIC DUPLEXER, AND COMMUNICATION APPARATUS USING THE SAME

摘要

PURPOSE: A dielectric filter, a dielectric duplexer and a communication device are provided to easily change an attenuation characteristic without changing its outside dimensions to improve its spurious-signal characteristic. CONSTITUTION: A pair of through holes(2a,2b) extend through a rectangular parallel-piped dielectric block from a left-hand surface thereof toward a right-hand surface thereof. An outer conductor(4) is formed on five of the outer surfaces of the dielectric block(1) except the left-hand surface which is an open surface. Each of the through holes(2a,2b) have a stepped shape in which the diameters are larger at the open surface side of the dielectric block(1). Inner conductors(3a,3b) are formed on the inner surfaces of the through holes(2a,2b), respectively, to form respective resonant cavities. The resonant cavities are short circuited to the outer conductor(4) at the right-hand surface of the dielectric block(1).