TY  - JOUR
AU  - Loudkov, D.
AU  - Tong, C-Y E.
AU  - Blundell, R.
AU  - Kaurova, N.
AU  - Grishina, E.
AU  - Voronov, B.
AU  - Gol’tsman, G.
PY  - 2005
DA  - 2005//
TI  - An investigation of the performance of the superconducting HEB mixer as a function of its RF embedding impedance
T2  - IEEE Trans. Appl. Supercond.
JO  - IEEE Trans. Appl. Supercond.
SP  - 472
EP  - 475
VL  - 15
IS  - 2
KW  - waveguide NbN HEB mixers
AB  - 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.
UR  - https://doi.org/10.1109/TASC.2005.849879
DO  - 10.1109/TASC.2005.849879
N1  - exported from refbase (https://db.rplab.ru/refbase/show.php?record=1464), last updated on Mon, 17 May 2021 16:40:07 -0500
ID  - Loudkov_etal2005
ER  -