Title :
The Direct Detection Effect in the Hot-Electron Bolometer Mixer Sensitivity Calibration
Author :
Cherednichenko, Sergey ; Drakinskiy, Vladimir ; Berg, Therese ; Kollberg, Erik L. ; Angelov, Iltcho
Author_Institution :
Dept. of Microtechnol. & Nanosci., Chalmers Univ. of Technol., Goteborg
fDate :
3/1/2007 12:00:00 AM
Abstract :
We investigate an error in the noise temperature measurements of the hot-electron bolometer mixers caused by the so-called "direct detection effect". The effect originates in the changing of the mixer parameters when the mixer is loaded on calibration black body sources at different temperatures (300 and 77 K). A correction factor was obtained from the mixer output power versus the bias current dependence, measured by: 1) the local oscillator (LO) power tuning: 2) mixer heating: and 3) application of an external RF source. Furthermore, the direct detection effect was assessed by elimination of the heterodyne response using a LO frequency, which is far off the mixer RF band. We show that the direct detection effect can be mitigated by using an isolator between the mixer and the IF amplifier
Keywords :
bolometers; calibration; hot carriers; submillimetre wave detectors; submillimetre wave mixers; superconducting mixers; superconducting photodetectors; 300 K; 77 K; IF matching; calibration black body sources; direct detection effect; heterodyne response; hot-electron bolometer; local oscillator; mixer heating; mixer sensitivity calibration; noise temperature measurements; Bolometers; Calibration; Current measurement; Local oscillators; Power generation; Power measurement; Radio frequency; Temperature dependence; Temperature measurement; Temperature sensors; Hot-electron bolometer (HEB); IF matching; mixer; noise temperature; terahertz;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2007.891470
