Backward wave oscillators with rippled wall resonators: Analytic theory and numerical simulation

Abstract

In this paper, a comprehensive theoretical treatment is developed for backward wave oscillators composed of a relativistic electron beam guided by a strong magnetic field through a slow wave structure consisting of a cylindrical waveguide with a sinusoidally varying wall radius. This analysis, equally applicable to traveling wave tube operation, includes both a linearized theory of small-amplitude perturbations and numerical simulations of the saturated, large-amplitude operating regime. The variation of device operating characteristics with system parameters is examined in detail. Comparisons of the analytic and numerical results with experiments and additional calculations show excellent agreement and justify a high degree of confidence in the validity of the theory.

Design of a high-efficiency dual-band coaxial relativistic backward wave oscillator with variable coupling impedance and phase velocity

“…The same interaction pattern repeated with the 1st space harmonic of the TM 01 mode with 2.37 cm −1 ≤ k 0 ≤ 2.75 cm −1 . The maximum value of ω i with TM 01 mode is much larger than that of quasi-TEM mode, which reveals that the operation mode of SWS1 is TM 01 mode (Swegle et al, 1985). The dominant frequency of SWS1 where the maximum ω i occurs is 9.7 GHz.…”

“…The high-frequency characteristics of the system, including the beam-wave interaction regions and operation mode of each SWS section, as well as the approximate values of the two dominant frequencies (Swegle et al, 1985;Zheng et al, 1995), could be acquired by linear wave dispersion analysis of coaxial SWS. The coaxial SWS system, as depicted in Figure 2, consists of a coaxial cylindrical waveguide with inner and outer wall radii R w1 and R w2 varying according to the relation:…”

Development of a 2 MW relativistic backward wave oscillator

“…Backward wave oscillator (BWO) is one of the devices that efficiently converts energy of an electron beam into electromagnetic radiation at microwave frequencies [1][2][3][4][5][6][7][8][9][10][11]. It essentially consists of an electron beam, confined radially by a strong magnetic field, propagating through a slow wave structure (SWS).…”

<title>Pierce-type dispersion relation for an intense relativistic electron beam interacting with a slow-wave structure</title>

“…In this section we review the basic formulation of the problem given by Swegle, Poukey and Leifeste [6]. For present purposes, we consider a thin annular relativistic electron beam propagating at axial velocity Ve-, through an infinitely long cylindrical waveguide whose radius is given by the periodic function…”