PT Unknown AU Gao, JR Hajenius, M Baselmans, JJA Klapwijk, TM de Korte, PAJ Voronov, B Gol'tsman, G TI NbN hot electron bolometer mixers with superior performance for space applications SE Proc. Int. workshop on low temp. electronics PY 2004 BP 11 EP 17 DE NbN HEB mixers; applications PI Noordwijk ER