Title :
Ka-band second-harmonic cusp-gun gyro-TWT
Author :
Harriet, S.B. ; Mcermott, D.B. ; Hirata, Y. ; Chang, T.H. ; Chu, K.R. ; Luhmann, N.C., Jr.
Author_Institution :
Dept. of Appl. Sci., California Univ., Davis, CA, USA
Abstract :
Summary form only given, as follows. A 30 GHz second-harmonic sliced smooth-bore TE/sub 21/ gyro-TWT with a cusp gun has been designed to double the efficiency of our previous 200 kW, 12% efficient, MIG TE/sub 21//sup (2)/ gyro-TWT. The new circuit is also sliced to destroy the odd-order azimuthal modes, but the axis-encircling electrons are no longer be confined to the maxima and minima of the linearly polarized mode. The 70 kV, 3.5 A, v/spl perp//v/sub z/=1.2, /spl Delta/v/sub z//v/sub z/=8%, axis-encircling electron beam is produced by a cusp gun delivered by Northrop Grumman. The single-stage amplifier is predicted by our large-signal simulation code to generate 50 kW at 30 GHz with 20% efficiency, 30 dB saturated gain and 3% constant-drive bandwidth. Linear theory has been used to determine the threshold start-oscillation beam current for absolute instability and the critical section lengths for the potential harmonic gyro-BWO interactions.
Keywords :
backward wave oscillators; electron guns; gyrotrons; microwave generation; microwave oscillators; microwave power amplifiers; microwave tubes; millimetre wave generation; millimetre wave oscillators; millimetre wave power amplifiers; millimetre wave tubes; stability; travelling wave tubes; 12 percent; 20 percent; 200 kW; 30 GHz; 30 dB; 50 kW; Ka-band second-harmonic cusp-gun gyro-TWT; MIG TE/sub 21//sup (2)/ gyro-TWT; Northrop Grumman; absolute instability; axis-encircling electrons; critical section lengths; cusp gun; gyro-BWO interactions; large-signal simulation code; linear theory; linearly polarized mode; odd-order azimuthal modes; potential harmonic gyro-BWO interactions; second-harmonic sliced smooth-bore TE/sub 21/ gyro-TWT; single-stage amplifier; threshold start-oscillation beam current; Bandwidth; Contracts; Coupling circuits; Electron beams; Gain; Gyrotrons; Physics; Polarization; Predictive models; Signal generators;
Conference_Titel :
Plasma Science, 2000. ICOPS 2000. IEEE Conference Record - Abstracts. The 27th IEEE International Conference on
Conference_Location :
New Orleans, LA, USA
Print_ISBN :
0-7803-5982-8
DOI :
10.1109/PLASMA.2000.854880