DocumentCode :
1524226
Title :
Theory and experiment of ultrahigh-gain gyrotron traveling wave amplifier
Author :
Chu, Kwo Ray ; Chen, Han-Ying ; Hung, Chien-Lung ; Chang, Tsun-Hsu ; Barnett, Larry R. ; Chen, Shih-Hung ; Yang, Tz-Te ; Dialetis, Demosthenes J.
Author_Institution :
Dept. of Phys., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Volume :
27
Issue :
2
fYear :
1999
fDate :
4/1/1999 12:00:00 AM
Firstpage :
391
Lastpage :
404
Abstract :
Physics and technology issues of importance to the high-gain gyrotron traveling wave amplifier (gyro-TWT) are investigated in theory and experiment. The gyro-TWT is known to be highly susceptible to spurious oscillations, especially in high gain operations. In the current study, oscillations of various origins are classified and characterized with detailed theoretical modeling. They are shown to be intricately connected to the interplay between the absolute/convective instabilities, circuit losses, and reflective feedback. Knowledge of these processes leads to the concept of an ultra high gain scheme which employs distributed wall losses for the suppression of spurious oscillations. A proof-of-principle Ka-band gyro-TWT experiment stable at zero drive has produced 93 kW saturated peak power at 26.5% efficiency and 70 dB gain, with a 3 dB saturated output power bandwidth of 3 GHz. The saturated gain is more than 30 dB beyond that previously achieved
Keywords :
feedback; gyrotrons; millimetre wave generation; travelling wave tubes; 26.5 percent; 3 GHz; 70 dB; 93 kW; Ka-band; absolute/convective instabilities; circuit losses; distributed wall losses; high gain operations; reflective feedback; saturated output power bandwidth; saturated peak power; spurious oscillations; traveling wave amplifier; ultrahigh-gain gyrotron; Bandwidth; Cyclotrons; Electron beams; Feedback; Gyrotrons; Millimeter wave technology; Physics; Power amplifiers; Power generation; Resonance;
fLanguage :
English
Journal_Title :
Plasma Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0093-3813
Type :
jour
DOI :
10.1109/27.772266
Filename :
772266
Link To Document :
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