@InProceedings{Merkel_etal1998, author="Merkel, H. F. and Yagoubov, P. A. and Kroug, M. and Khosropanah, P. and Kollberg, E. L. and Gol{\textquoteright}tsman, G. N. and Gershenzon, E. M.", title="Noise temperature and absorbed LO power measurement methods for NbN phonon-cooled hot electron bolometric mixers at terahertz frequencies", booktitle="Proc. 28th European Microwave Conf.", year="1998", volume="1", pages="294--299", optkeywords="NbN HEB mixers", abstract="In this paper the absorbed LO power requirements and the noise performance of NbN based phonon-cooled hot electron bolometric (HEB) quasioptical mixers are investigated for RF frequencies in the 0.55-1.1 range The minimal measured DSB noise temperatures are about 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz and 1250 K at 1.1 THz. The increase in noise temperature at 1.1THz is attributed to water absorption. The absorbed LO power is measured using a calorimetric approach. The results are subsequently corrected for lattice heating. These values are compared to results of a novel one dimensional hot spot mixer models and to a more traditional isotherm method which tends to underestimate the absorbed LO power for small bias powers. Typically a LO power between 50nW and 100nW is needed to pump the device to the optimal operating point.", optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1580), last updated on Tue, 25 May 2021 17:21:10 -0500", doi="10.1109/EUMA.1998.338003", opturl="https://doi.org/10.1109/EUMA.1998.338003" }