Gain banwidth for superconducting hot electron bolometers at terahertz waveband

Intermediate frequency (IF) gain bandwidth (GBW) of terahertz (THz) heterodyne detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) has been studied in details. Two different methods, resulting in same IF GBW value of about 3.5 GHz are reported here.