LOW-POWER SUBMILLIMETER-WAVE MIXING AND RESPONSIVITY PROPERTIES OF YBA2CU3O7 HOT-ELECTRON BOLOMETERS

Low power characteristics of superconducting hot-electron bolometric m ixers using YBa2Cu3O7 are reported. Near 77 K, these mixers have a res ponsivity of 780 V/W using 8 nW of local oscillator (LO) power at 585 GHz. The responsivity can be shown to be truly bolometric. Heterodyne mixing at 87 GHz shows an overall conversion gain of -47 dB at 1.8 GHz intermediate frequency, using 3.3 mW of incident LO power. The intrin sic conversion gain is estimated to be -16 dB with 1 mu W of LO power, close to the calculated optimal values. (C) 1997 American Institute o f Physics.