High Efficiency Dual Mode Octave Bandwidth Traveling Wave Tube.
Final technical rept. Jan 74-Jun 75,
HUGHES AIRCRAFT CO TORRANCE CALIF ELECTRON DYNAMICS DIV
Pagination or Media Count:
Techniques resulting in high overall efficiency over extended bandwidths have been considered in this study effort. Some of the techniques have been pursued during previous efficiency studies in which high efficiencies have been demonstrated on CW and pulsed traveling-wave tubes. The present study is complicated by both the high average power requirement and the 10 dB pulse-up dual mode capability. In addition, periodic permanent magnet focusing has added to the complexity of the design task. Experimental cold testing dealing with helices of different pitch has been performed. Suitable shaping methods have resulted in high interaction impedances with small phase velocity variations over octave bandwidths. Large signal computer evaluations considering beam-circuit wave velocity resynchronization schemes have been conducted. An existing experimental dual mode electron gun has been scaled and structurally adapted for PPM focusing. A satisfactory match has been designed and demonstrated for both input and output transducers. A helix phase velocity taper is used to improve basic inter-action efficiencies. A three-stage, double depressed collector is added to further improve overall conversion efficiency.
- Electrical and Electronic Equipment