Josephson-junction mm-wave mixer

A mixer based on a Josephson point junction operating at a wavelength of 2 mm is developed. The mixer uses an intermediate microwave frequency of 10 GHz. The conversion losses are estimated from the value of the ratio of the klystron signal power reaching the contact to the power of the intermediate-frequency signal at the mixer output. It is found that the conversion losses referred to the contact are less than or equal to 12 dB. The noise temperature of the mixer estimated from the intrinsic noise of the Josephson contact at the intermediate frequency in the presence of a strong heterodyne signal is determined to be approximately 180 K.