Parametric Oscillations in High Power Microwave Amplifiers.
Abstract
A Crossed Field Amplifier (CFA) model for parametric oscillations was developed which fulfills the basic requirements, empirically defines, for their existence; namely, the model requires their presence, preferably in overdrive conditions. The model then defines a fixed frequency f sub o located at the lower edge of the bandgap of the periodic slow wave structure, and predicts the simultaneous existence of a very-low-frequency oscillation. The existence of this low frequency oscillation has been verified experimentally. The presented model further predicts the power gain is obtained at low frequencies (f sub 1) and frequencies close to the bandgap (f sub 2). This power is obtained from the pump signal, and thus apparently from the second harmonic of the drive signal. The mathematical fundamentals of the model proposed for the traveling wave tube in terms of the coupled-mode theory was established. As in the case of the CFA, waves with three different frequencies were considered, which means that 6 waves will have to be tracked, 3 in each direction. The boundary conditions must then apply at each of the many interfaces between the empty and filled waveguide sections. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1979
- Accession Number
- ADA082641
Entities
People
- Gunter Dohler