TY - CONF AU - Antipov, S. AU - Trifonov, A. AU - Krause, S. AU - Meledin, D. AU - Desmaris, V. AU - Belitsky, V. AU - Gol’tsman, G. PY - 2017 DA - 2017// TI - Gain bandwidth of NbN HEB mixers on GaN buffer layer operating at 2 THz local oscillator frequency T2 - Proc. 28[super:th] Int. Symp. Space Terahertz Technol. BT - Proc. 28[super:th] Int. Symp. Space Terahertz Technol. SP - 147 EP - 148 KW - NbN HEB mixers KW - GaN buffer-layer KW - IF bandwidth AB - 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. N1 - exported from refbase (https://db.rplab.ru/refbase/show.php?record=1175), last updated on Sat, 01 May 2021 00:48:23 -0500 ID - Antipov_etal2017 ER -