Analytical Study of the Interaction Structure of Vane-Loaded Gyro-Traveling Wave Tube Amplifier

Abstract

Abstract-This article discusses the-state-of-the-art of the vaneloaded gyrotron traveling wave tube (gyro-TWT) amplifier, which is device of increasing importance for high resolution radar and high information density communication systems because of its high-power and broad bandwidth capabilities. Vane loading is identified as a means to achieve a low-beam energy, high-harmonic, low-magnetic field, mode-selective and stable operation of a gyro-TWT. Thus, the development of a simple approach to the analysis of the interaction structure of vane-loaded gyro-TWT has been identified as a problem of practical relevance.

Te and Tm Modes of a Vane-Loaded Circular Cylindrical Waveguide for Gyro-TWT Applications

“…Notwithstanding the impressive list of applications of the vaneloaded structure cited in the previous paragraph, the 'derivation' of the dispersion equations for this structure attempted in [1] is seriously flawed rendering the results and conclusions of [2][3][4][5][6][7][8][9][10][11][12] to be of questionable validity for the following reason: The azimuthal dependence of the assumed form of the solution for the field components in the annular region containing the vanes does not permit the boundary condition on the radial component of the electric field, viz., the radial electric field component should vanish on the lateral boundaries (located on the radial planes passing through the waveguide axis) of the perfectly conducting vanes, to be satisfied; more fundamentally the assumed form of solution is not capable of ensuring a null electromagnetic field everywhere inside the vane region.…”

The Experimental Results of a Low Power X-Band Free Electron Maser by Electron Pre-Bunching

“…The free electron maser (FEM) is a source of microwave power which makes use of the interaction between the electron beam and electromagnetic radiation [1,2]. In a uniform electron beam, the contributions of individual electrons to the random field are random in phase.…”

Propagation Characteristics of a Variant of Disc-Loaded Circular Waveguide

“…In these devices, one may see the periodic beam-wave interaction structures holding either azimuthal or axial periodicity [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. The azimuthal periodicity in interaction structure may be seen, for example: in travelling-wave magnetrons [14] for π-mode operation, in gyrotrons [21][22][23][24] for mode rarefaction, in conventional helixTWTs [17] for broadbanding, in gyro-travelling wave tubes (gyroTWTs) [25,26] for higher interaction impedance and, in turn, for higher device-gain. The axial periodicity in interaction structure may be seen, for example, in conventional helix-TWT [17] for higher device-gain, in coupled-cavity TWT [17] for getting fundamentalmode backward-wave characteristics, and in gyro-TWT [27][28][29][30][31][32][33][34][35][36][37][38][39] for broadbanding.…”

“…and even in the vacuum electronic devices, such as, linear/particle accelerators [11,12], backward-wave oscillators (BWOs) [13], magnetrons [14], coupledcavity and helix travelling-wave tubes (TWTs) [15][16][17][18][19], cyclotron masers [20,21], gyrotron sources [21][22][23][24] and amplifiers [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], etc.. In these devices, one may see the periodic beam-wave interaction structures holding either azimuthal or axial periodicity [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]…”