Patent ID: 6369668
Filing Date: 2002-04-09
Classification: H01P

Abstract:
A duplexer comprising:&lgr;/4-type dielectric coaxial resonators having open end surfaces and short end surfaces constituting a transmitting-side filter; a first coupling element which couples said resonators of said transmitting-side filter; &lgr;/4-type dielectric coaxial resonators having open end surfaces and short end surfaces constituting a receiving-side filter; and a second coupling element which couples said resonators of said receiving-side filter; wherein all of the respective dielectric coaxial resonators constituting the transmitting-side filter and all of the respective dielectric coaxial resonators constituting the receiving-side filter are alternately disposed side by side; the open end surfaces of the respective dielectric coaxial resonators constituting the transmitting-side filter are disposed in opposite directions from the open end surfaces of the respective dielectric coaxial resonators constituting the receiving-side filter; the first coupling element is arranged adjacent the open-end-surface side of the dielectric coaxial resonators constituting the transmitting-side filter and remote from the open-end-surface side of the receiving-side filter; the second coupling element is arranged adjacent the open-end-surface side of the dielectric coaxial resonators constituting the receiving-side filter and remote from the open-end-surface side of said transmitting-side filter; the second coupling element comprises an inductor; and the inductor is arranged adjacent to the short end surface of the dielectric coaxial resonators constituting the receiving-side filter.