@Article{Loudkov_etal2005,
author="Loudkov, D.
and Tong, C-Y E.
and Blundell, R.
and Kaurova, N.
and Grishina, E.
and Voronov, B.
and Gol{\textquoteright}tsman, G.",
title="An investigation of the performance of the superconducting HEB mixer as a function of its RF embedding impedance",
journal="IEEE Trans. Appl. Supercond.",
year="2005",
volume="15",
number="2",
pages="472--475",
optkeywords="waveguide NbN HEB mixers",
abstract="We have conducted an investigation of the optimal embedding impedance for a waveguide superconducting hot-electron bolometric (HEB) mixer. Three mixer chip designs for 800 GHz, offering nominal embedding resistances of 70 /spl Omega/, 35 /spl Omega/, and 15 /spl Omega/, have been developed. We used both High Frequency Structure Simulator (HFSS) software and scale model impedance measurements in the design process. We subsequently fabricated HEB mixers to these designs using 3-4 nm thick NbN thin film. Receiver noise temperature measurements and Fourier Transform Spectrometer (FTS) scans were performed to determine the optimal combination of embedding impedance and normal-state resistance for a 50 Ohm IF load impedance. A receiver noise temperature of 440 K was measured at a local oscillator frequency 850 GHz for a mixer with normal state resistance of 62 /spl Omega/ incorporated into a circuit offering a nominal embedding impedance of 70 /spl Omega/. We conclude from our data that, for low noise operation, the normal state resistance of the HEB mixer element should be close to the embedding impedance of the mixer mount.",
optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1464), last updated on Mon, 17 May 2021 16:40:07 -0500",
doi="10.1109/TASC.2005.849879",
opturl="https://doi.org/10.1109/TASC.2005.849879"
}