DUAL MODE BAND-PASS FILTER, DUPLEXER AND RADIO COMMUNICATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a dual mode band-pass filter with an excellent degree of design freedom capable of easily obtaining a desired bandwidth and the filter characteristics at the center frequency. SOLUTION: The dual mode band-pass filter 1 includes: a resonator electrode 3 provided to a dielectric substrate 2; input output coupling circuits 5, 6 coupled to the resonator electrode 3; ground electrodes 9, 10 arranged in opposition to the resonator electrode 3 via part of the dielectric substrate; and a via-hole electrode 4 projected orthogonally to the resonator electrode in the dielectric substrate from at least one direction of the resonator electrode 3 so that two resonance modes caused in the resonator electrode 3 are combined. COPYRIGHT: (C)2005,JPO&NCIPI