Title :
Stabilization Scheme for Hot-Electron Bolometer Receivers Using Microwave Radiation
Author :
Ryabchun, Sergey ; Tong, Cheuk-Yu Edward ; Blundell, Raymond ; Gol´tsman, Gregory
Author_Institution :
Harvard-Smithsonian Center for Astrophys., Cambridge, MA
Abstract :
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.
Keywords :
bolometers; current fluctuations; niobium compounds; submillimetre wave mixers; submillimetre wave receivers; superconducting microwave devices; Allan time; current fluctuations; feedback control loop; gap frequency; hot-electron bolometer mixers; microwave radiation; stabilization; terahertz receivers; time 10 s; Allan variance; hot-electron bolometer (HEB) mixer; radiometer equation; terahertz receivers;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Conference_Location :
12/12/2008 12:00:00 AM
DOI :
10.1109/TASC.2008.2008398
