Gain bandwidth of NbN HEB mixers on GaN buffer layer operating at 2 THz local oscillator frequency
Paper in proceedings, 2017

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.

Author

Sergey Antipov

Andrey Trifonov

Sascha Krause

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Denis Meledin

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Vincent Desmaris

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Victor Belitsky

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Gregory Goltsman

28th International Symposium on Space Terahertz Technology, March 13-15, 2017

Infrastructure

Onsala Space Observatory

Nanofabrication Laboratory

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

Nano Technology

Condensed Matter Physics

More information

Created

12/22/2017