PT Journal
AU Ryabchun, S
   Tong, CE
   Blundell, R
   Gol'tsman, G
TI Stabilization scheme for hot-electron bolometer receivers using microwave radiation
SO IEEE Trans. Appl. Supercond.
JI IEEE Trans. Appl. Supercond.
PY 2009
BP 14
EP 19
VL 19
IS 1
DI 10.1109/TASC.2008.2008398
DE HEB; mixer; Allan variance; stabilization; radiometer equation
AB We present the results of a stabilization scheme for terahertz receivers based on NbN hot-electron bolometer (HEB) mixers that uses microwave radiation with a frequency much lower than the gap frequency of NbN to compensate for mixer current fluctuations. A feedback control loop, which actively controls the power level of the injected microwave radiation, has successfully been implemented to stabilize the operating point of the HEB mixer. This allows us to increase the receiver Allan time to 10 s and also improve the temperature resolution of the receiver by about 30% in the total power mode of operation.
ER