Dielectric filter, dielectric duplexer, and communication apparatus

摘要

A dielectric filter, a dielectric duplexer, and a communication apparatus using them allow balanced input and/or output to be implemented without requiring a balun. Using a dielectric block, two lambd/2 resonators are individually formed using either inner-conductor-forming openings with inner conductors therein, or stripline-type conductors, both of said conductors having both ends open-circuited, and said conductors being capacitively coupled together. Terminal electrodes coupled to the vicinities of two open-circuited ends of one of the resonators are used as balanced terminals on one side, and terminal electrodes coupled to the vicinities of the two open-circuited ends of the other one of the resonators are used as balanced terminals on the other side.