Rapid startup in relativistic backward wave oscillator by injecting external backward signal

Abstract

Investigation on accelerating the building up of oscillation and achieving a rapid startup in powerful relativistic backward wave oscillator by injecting a weak external backward signal is carried out in this paper. Synchronizing the signal with the backward wave excited by intense electron beam extracting with slow wave structure, the initial noise is greatly reduced and mode competition is restrained. The analysis is demonstrated by high power X-band backward wave oscillator experiment, in which a plasma switch is designed to realize the backward signal injection. The results show that the significant reduction of microwave output delay is attained and the start time of oscillation is ahead of 10 ns with the energy conversion efficiency increases about 62%.

Injection locking of a two-mode electron oscillator with close frequencies

“…In addition, we perform direct numerical integration of Eq. (6). The results of the bifurcation analysis and numerical simulations are in excellent agreement with each other.…”

“…Such regimes correspond to fixed-point solutions of Eq. (6). For that purpose, we use the public-domain software XPPAUT, 16 which allows performing a comprehensive bifurcation analysis for fixed points of dynamical systems described by ODEs.…”

“…The injection locking allows for controlling the radiation frequency and phase of high-power microwave sources, [1][2][3][4][5] as well as reducing transient times. 5,6 Also, a low-power external driving of a high-power oscillator may result in the fast frequency step tuning owing to the mode switching effect. [7][8][9] Nevertheless, the fundamentals of the mode switching are still poorly understood.…”

Peculiarities of Operation of a Relativistic Backward-Wave Oscillator Driven by an External Electromagnetic Signal

“…Such signals are proposed not only for direct amplification of the input signal, but to affect self-oscillators as well (see, e.g., [1][2][3][4][5][6]). In the latter case, the possibilities of synchronizing the frequency and phase of self-oscillations [3] and reducing the duration of transient processes [4][5][6] are studied.…”

“…Such signals are proposed not only for direct amplification of the input signal, but to affect self-oscillators as well (see, e.g., [1][2][3][4][5][6]). In the latter case, the possibilities of synchronizing the frequency and phase of self-oscillations [3] and reducing the duration of transient processes [4][5][6] are studied. One should mention at once the specific feature of using controlling high-frequency signals in high-power relativistic electronics, which is related to the short radiation pulse, specifically, the fact that as a rule, the output signal contains not more than several hundreds of periods of high-frequency oscillations.…”