TRANSVERSE WAVE INTERACTIONS BETWEEN ROTATING ELECTRON BEAMS AND WAVE GUIDES.
UTAH UNIV SALT LAKE CITY MICROWAVE DEVICE AND PHYSICAL ELECTRONICS LAB
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Microwave interactions resulting in oscillation and amplification have been observed in cases involving a beam of rotating electrons in a wave guide. The interaction is a cyclotron resonance phenomenon which occurs when the rotating electrons are synchronized with the wave guide fields. Application of a general coupled-mode theory to specific rotating beam configurations is made. The dispersion properties of the normal beam modes and normal circuit modes are considered to find possible cases of synchronism which may result in favorable interactions. The coupled-mode equations are solved for important cases with the help of simplifying approximations to find the propagation constants of the waves which can exist in the system. Application of boundary conditions at the input to the interaction circuit completes the interaction description. An expression for gain for the wave guide circuit mode is defined. These calculations show that both backward-wave oscillation and traveling-wave amplification are possible in this type of device, but that the backward-wave interaction dominates. An experimental device has been built with a rotating electron beam in a rectangular X-band wave guide circuit. Experimental investigations reveal that the device is characterized by a backward-wave oscillation interaction. The observed interaction is found to be consistent with the results of the coupled-mode analysis, and the coupled-mode analysis appears to give an accurate description of the interaction mechanism. Oscillator pulsed power of 720 watts with an efficiency of about 10 percent and frequency tuning with magnetic field between 6.55 and 22.0 kmc has been observed. Author
- Electrical and Electronic Equipment
- Electricity and Magnetism
- Radiofrequency Wave Propagation