GAIN BANDWIDTH AND NOISE CHARACTERISTICS OF MILLIMETER-WAVE YBA2CU3O7HOT-ELECTRON BOLOMETER MIXERS

Conversion gain bandwidth and noise characteristics are reported for l attice-cooled superconducting YBa2Cu3O7 hat-electron bolometers acting as low-power, wide-bandwidth heterodyne mixers at 75 and 585 GKz. Nea r 77 K, these mixers show intrinsic conversion gain as high as -16 dB using similar to 1 mu W of local oscillator power. The measured gain b andwidth is well described by a single Lorentzian with -3 dB frequency of 5-9 GHz. Measurements of output noise combined with conversion gai n indicate an optimal input noise temperature of similar to 5000 K, si gnificantly lower than calculations predict. (C) 1998 American Institu te of Physics.