BAND-PASS FILTER PROVIDED WITH DIELECTRIC RESONATOR

摘要

PROBLEM TO BE SOLVED: To suppress the generation of unrequired waves near a basic mode by providing a step type dielectric resonator for moving high-order mode characteristics to a frequency band higher than the basic mode and suppressing unrequired wave characteristics. SOLUTION: The step type dielectric resonators 31a-31c respectively mounted to the voids 32a-32c of a housing 32 are provided and radio signals are impressed to an input connector 33. Electromagnetic waves are induced between a coupling group 35 and a first step type resonator 31a and the mode of basic resonance and a high-order mode resonated through the first step type resonator 31a are transmitted to a second step type resonator 31b. At the time, the unrequired wave characteristics generated by the resonance of the high-order mode are moved to a frequency far higher than the basic mode. Then, only the signals of a desired frequency band are transmitted to an output connector 33' while coupling signal electric power through a coupling window 34a provided between the first step type resonator 31a and the second step type resonator 31b.