Title :
Small-signal two-dimensional model of parasitic backward-wave oscillation in a monofilar-helix traveling-wave tube
Author :
Belyavskiy, Eugene D. ; Shevelenok, Ivan V. ; Khotiaintsev, Sergei N.
Author_Institution :
Fac. of Electron., Nat. Tech. Univ. of Ukraine, Kiev, Ukraine
Abstract :
We present a mathematical linear 2D model of the interaction of the synchronous forward and backward harmonics of the electromagnetic wave, existing in the slow-wave circuit, with the electron beam in a monofilar-helix traveling-wave tube (TWT) under periodic permanent magnetic (PPM) focusing. We accounted for the effect of the electron beam alternating rotation in the PPM focusing field, magnetic field amplitude and periodicity, and the specific coupling of the electron beam with the circuit wave. This coupling takes place in the monofilar-helix TWT only and decreases its stability with respect to the parasitic backward-wave oscillation in comparison to other types of helix TWT.
Keywords :
circuit stability; coupled circuits; electron beam focusing; harmonics; oscillations; travelling wave tubes; PPM focusing field; TWT stability; backward harmonics; electron beam EM wave interactions; electron beam alternating rotation; electron beam circuit wave coupling; magnetic field amplitude; magnetic field periodicity; monofilar-helix traveling-wave tube; parasitic backward-wave oscillation; periodic permanent magnetic focusing; slow-wave circuit EM waves; small-signal 2D oscillation model; synchronous forward harmonics; Coupling circuits; Current density; Electromagnetic scattering; Electron beams; Electron tubes; Magnetic circuits; Magnetic fields; Mathematical model; Optical coupling; Radio frequency;
Conference_Titel :
Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004. Proceedings of the 9th International Seminar/Workshop on
Print_ISBN :
966-02-3253-5
DOI :
10.1109/DIPED.2004.242937
