Title :
Recent development on terahertz spectroscopy and measurement with phase locked backward-wave oscillators
Author :
Tretyakov, M.Yu.
Author_Institution :
Inst. of Appl. Phys., Acad. of Sci., Nizhny Novgorod, Russia
Abstract :
Discusses a really fast frequency scanning option for millimeter and submillimeter-wave synthesizers which opens as a consequence new possibilities for precise microwave measurements. This becomes possible due to development of synthesized radio frequency source with a discreteness of 0.03 Hz and switching time of about 200 ns without phase jumps. The source is based on 0-50 MHz direct digital synthesizer microchip. Frequency modulation by sine, square-wave, triangle, saw-tooth and other desired functions with precisely known frequency deviation and period of modulation is possible. The signal from the source is used as a reference in a phase detector of BWO PLL so the tube output radiation frequency follows the law of the radio source frequency change. Fast frequency scan/modulation without phase jumps of phase-locked BWO is available now within 0.2 GHz.
Keywords :
backward wave oscillators; direct digital synthesis; phase locked oscillators; submillimetre wave measurement; submillimetre wave spectroscopy; 0 to 50 MHz; 200 ns; direct digital synthesizer microchip; frequency deviation; frequency scanning option; period of modulation; phase locked backward-wave oscillators; precise microwave measurements; submillimeter-wave synthesizers; switching time; synthesized radio frequency source; terahertz spectroscopy; tube output radiation frequency; Frequency measurement; Frequency modulation; Frequency synthesizers; Microwave measurements; Phase detection; Phase frequency detector; RF signals; Radio frequency; Spectroscopy; Submillimeter wave measurements;
Conference_Titel :
Infrared and Millimeter Waves, 2000. Conference Digest. 2000 25th International Conference on
Conference_Location :
Beijing, China
Print_ISBN :
0-7803-6513-5
DOI :
10.1109/ICIMW.2000.892936
