Analysis of a Vane-Loaded Gyro-TWT for the Gain-Frequency Response

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

“…The basic approach to finding the cold dispersion relation of the structure as shown in Fig. 3 (without electron beam) consists in finding a system of simultaneous equations in the Fourier components of field constants [58,62,[70][71][72][73][74][75][76]. For this purpose, we follow the usual approach of substituting the field expressions in the relevant boundary conditions of the structure, and find the condition for non-trivial solution.…”

“…The Pierce-type gain equation may be derived from the dispersion relation (14) by an approach [59][60][61][62]70], which is similar to what is followed in obtaining the gain equation of a conventional TWT. For this purpose, the solution of (14) is sought around the cold propagation constant β of the waveguide, such that −jk z = −jβ+βCδ, with Cδ << 1, where C and δ are arbitrarily chosen dimensionless quantities.…”

“…Following the same method, one may derive, from the solution of the cubic equation (18), the gain equation of a gyro-TWT. The method, which is outlined in [59][60][61][62]70], leads to the following gain formula for a gyro-TWT in terms of the three solutions δ 1 , δ 2 and δ 3 , say, of (18), and x 1 , the real part of δ 1 , supposedly positive (corresponding to a growing wave solution):…”

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

“…In a paper [5] published in 2002, Singh et al have used the dispersion relations of [1] for finding the dispersion characteristics of 'TE 01 ' and 'TE 21 ' modes for a typical set of vane-parameter values. In the papers by Singh et al [6][7][8][9][10], various methods of analyzing/improving the frequency-response characteristics of gyro-TWT amplifiers have been proposed based again on the results from [1]. The papers [11] by Singh and Basu and [12] by Singh were devoted to analytical studies of the interaction structure of vane-loaded gyro-TWT amplifiers starting again from the cold-wave dispersion relations appearing in [1].…”

“…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.…”