Phase-locking of a second-harmonic gyrotron oscillator using a quasi-optical circulator to separate injection and output signals

Author

Guo, Hezhong ; Hoppe, Daniel J. ; Rodgers, John ; Perez, Raul M. ; Tate, Jeffrey P. ; Conroy, Bruce L. ; Granatstein, Victor L. ; Bhanji, A.M. ; Latham, Peter E. ; Nusinovich, Gregory S. ; Naiman, Matthew L. ; Chen, Shiaw-Huei

Author_Institution

Inst. for Plasma Res., Maryland Univ., College Park, MD, USA

Volume

23

Issue

5

fYear

1995

fDate

10/1/1995 12:00:00 AM

Firstpage

822

Lastpage

832

Abstract

Phase-locking in a 34.5-GHz special complex cavity gyrotron oscillator operating at the second harmonic of the electron cyclotron frequency was studied. Injection of the locking power was made via a quasi-optical circulator connected to the gyrotron output. Locking bandwidth was measured by comparing the phase of the injection signal and output signal using a balanced mixer. Locking was observed with input power level as low as 40 dB below the gyrotron output power. The locking bandwidth is, however, narrower than in gyrotrons operating at the fundamental cyclotron frequency which may be attributed to the longer resonant cavity in the second harmonic gyrotron and the corresponding larger value of external quality factor. The measurements are roughly in agreement with predictions of Adler´s phase-locking equation which is given for our system in terms of powers propagating in the output waveguide toward and away from the gyrotron cavity

Keywords

Q-factor; gyrotrons; harmonic generation; harmonic oscillators (circuits); microwave oscillators; millimetre wave oscillators; optical circulators; phase locked oscillators; 34.5 GHz; Adler´s phase-locking equation; electron cyclotron frequency; external quality factor; injection signals; locking bandwidth; output signals; output waveguide; phase-locking; quasi-optical circulator; resonant cavity; second-harmonic gyrotron oscillator; Bandwidth; Cyclotrons; Electrons; Frequency; Gyrotrons; Oscillators; Phase measurement; Power generation; Q factor; Resonance;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.473201

Filename

473201