Impedance and Bandwidth Characterization of NbN Hot Electron Bolometric Mixers

We are presenting here our recent results of noise temperature and impedance measurements for NbN Hot Electron Bolometer (HEB) mixers. The noise temperature measurements were performed over a 1-8 GHz IF band using an LO frequency of about 1.6 THz using quasi-optical coupling and a single low noise HEMT MMIC amplifier. On the other hand, the impedance measurements were completed with a network analyzer in the presence of LO power and DC bias, over a 2-10 GHz frequency range. The experimental results of both sets of measurements are used to predict noise and gain bandwidth of our devices and for comparison with those obtained from the standard model.