PT Unknown AU Cherednichenko, S Kroug, M Merkel, H Kollberg, E Loudkov, D Smirnov, K Voronov, B Gol'tsman, G Gershenzon, E TI Local oscillator power requirement and saturation effects in NbN HEB mixers SE Proc. 12[super:th] Int. Symp. Space Terahertz Technol. PY 2001 BP 273 EP 285 DE NbN HEB mixers; LO power; local oscillator power; saturation effect; dynamic range AB The local oscillator power required for NbN hot-electron bolometric mixers (P LO ) was investigated with respect to mixer size, critical temperature and ambient temperature. P LO can be decreased by a factor of 10 as the mixer size decreases from 4×0.4 µm 2 to 0.6×0.13 µm 2 . For the smallest volume mixer the optimal local oscillator power was found to be 15 nW. We found that for such mixer no signal compression was observed up to an input signal of 2 nW which corresponds to an equivalent input load of 20,000 K. For a constant mixer volume, reduction of T c can decrease optimal local oscillator power at least by a factor of 2 without a deterioration of the receiver noise temperature. Bath temperature was found to have minor effect on the receiver characteristics. PI San Diego, CA, USA ER