Patent ID: 7218184

Claim:
A superconducting filter comprising: a dielectric substrate; an input feeder formed on one surface of the dielectric substrate and formed of a superconductor film, for inputting a radio-frequency signal; a resonator pattern formed on said one surface of the dielectric substrate and formed of a superconductor film, for filtering the radio-frequency signal inputted from the input feeder; an output feeder formed on said one surface of the dielectric substrate and formed of a superconductor film, for outputting the radio-frequency signal filtered by the resonator pattern; and a dielectric body mounted on said one surface of the dielectric substrate with a plurality of spacers disposed therebetween, the dielectric body covering a region including the resonator pattern, an end part of the input feeder on a side nearer the resonator pattern, the end part of the input feeder having a length not less than 80% of a positive integer multiple of a ¼ effective wavelength and not more than 120% of the positive integer multiple of the ¼ effective wavelength and an end part of the output feeder on a side nearer the resonator pattern, the end part of the output feeder having a length not less than 80% of the positive integer multiple of the ¼ effective wavelength and not more than 120% of the positive integer multiple of the ¼ effective wavelength, wherein the input feeder and the output feeder are partially covered by the dielectric body.