Title :
Effect of power reflection on the operation of a low-Q 8 GHz gyrotron
Author :
Muggli, P. ; Tran, M.Q. ; Tran, T.M. ; Mathews, H.G. ; Agosti, G. ; Alberti, S. ; Perrenoud, A.
Author_Institution :
Centre de Recherches en Phys. des Plasmas, Ecole Polytech. Federale de Lausanne, Switzerland
fDate :
9/1/1990 12:00:00 AM
Abstract :
The operating characteristics of a low-Q (Qcav=225), 8-GHz gyrotron oscillator operating in the TE011O mode and submitted to various mismatched loads are reported. Under matched conditions, output power up to 310 kW (η=35%) and maximum efficiency up to 43% were measured. In general, power reflection from loads with different phases and amplitudes leads to an output power decrease. Excessive reflections cause mode switching (TE011O to TE012 O) or even arcing inside the tube. The effect of power reflection is seen to increase rapidly with current and output power. Nevertheless, as predicted by calculations, the maximum output power is not reached under matched conditions but with a specific nonzero value of the complex reflection coefficient
Keywords :
gyrotrons; microwave oscillators; 310 kW; 35 to 43 percent; 8 GHz; TE011O mode; arcing; complex reflection coefficient; effect of power reflection; gyrotron oscillator; low Q gyrotron; matched conditions; maximum efficiency; maximum output power; mismatched loads; mode switching; operating characteristics; operation; output power decrease; power reflection from loads; Frequency; Gyrotrons; Impedance matching; Optical reflection; Oscillators; Plasmas; Power generation; Power measurement; Resonance; Tellurium;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
