CHARACTERISTICS OF MILLIMETER-WAVE DETECTION IN A FABRY-PEROT RESONATOR USING A YBCO-BIO COMPOSITE SUPERCONDUCTOR

A quasioptical technique with a hemispherical-type Fabry-Perot resonat or for measuring characteristics of millimeter wave detection using a YBCO-BiO composite superconductor has been successfully developed. Thi s Fabry-Perot resonator consists of a spherical mirror and a plane mir ror mounted on the cold head of the refrigerator, under a controlled t emperature of 40 to 300 K. The method offers the advantages of estimat ing irradiation power, easily controlling the sample temperature, anal yzing the mode of the irradiated millimeter waves and easily extending to higher frequencies. The superconducting millimeter wave detector h as been measured with this technique, with measured sensitivities of 4 6.5 V/W (70 K) to 160 V/W (35 K) at 50 GHz. These results are close to the theoretical values calculated numerically from the characteristic s of the detector. It was confirmed that the millimeter wave detection system using the Fabry-Perot resonator is suitable for estimating the sensitivity of the high-Tc superconducting millimeter wave detector.