@InProceedings{Antipov_etal2017,
author="Antipov, S.
and Trifonov, A.
and Krause, S.
and Meledin, D.
and Desmaris, V.
and Belitsky, V.
and Gol{\textquoteright}tsman, G.",
title="Gain bandwidth of NbN HEB mixers on GaN buffer layer operating at 2 THz local oscillator frequency",
booktitle="Proc. 28$^{th}$ Int. Symp. Space Terahertz Technol.",
year="2017",
pages="147--148",
optkeywords="NbN HEB mixers; GaN buffer-layer; IF bandwidth",
abstract="In this paper, we present IF bandwidth measurement results of NbN HEB mixers, which are employing NbN thin films grown on a GaN buffer-layer. The HEB mixers were operated in the heterodyne regime at a bath temperature of approximately 4.5 K and with a local oscillator operating at a frequency of 2 THz. A quantum cascade laser served as the local oscillator and a reference synthesizer based on a BWO generator (130-160 GHz) and a semiconductor superlattice (SSL) frequency multiplier was used as a signal source. By changing the LO frequency it was possible to record the IF response or gain bandwidth of the HEB with a spectrum analyzer at the operation point, which yielded lowest noise temperature. The gain bandwidth that was recorded in the heterodyne regime at 2 THz amounts to approximately 5 GHz and coincides well with a measurement that has been performed at elevated bath temperatures and lower LO frequency of 140 GHz. These findings strongly support that by using a GaN buffer-layer the phonon escape time of NbN HEBs can be significantly lower as compared to e.g. Si substrate, thus, providing higher gain bandwidth.",
optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1175), last updated on Sat, 01 May 2021 00:48:23 -0500"
}