Patent ID: 6515559
Filing Date: 2003-02-04
Classification: H01P

Abstract:
An in band-flat-group-delay type dielectric filter, comprising:a plurality of dielectric coaxial resonators: a coupling circuit comprising a combination of electrodes, with which respective internal conductors of the dielectric coaxial resonators are connected, so that the adjacently located dielectric coaxial resonators are coupled to one another through a coupling capacitor composed of the respective electrodes; and input/output terminals coupled to ends of the coupling circuit, wherein the dielectric coaxial resonators include dielectric coaxial resonators coupled to the input/output terminals and inter-stage dielectric coaxial resonators, and a characteristic impedance of the dielectric coaxial resonators coupled to the input/output terminals is different from that of the inter-stage dielectric coaxial resonators so as to broaden the passband of the dielectric filter.