Modified Dispersion Equation for Planar Open Tape Helix Travelling Wave Tube
07 Mar 2019-pp 101-104
TL;DR: In this article, the dispersion equation for a planar traveling wave tube with anisotropic conducting open helix structure is derived and the exact solution of a homogenous boundary value problem for Maxwell's equations is derived.
Abstract: The dispersion equation for a planar traveling wave tube with anisotropically conducting open helix structure is derived. Using, the accurate boundary conditions along all the sides of the planar TWT and along the winding direction of the TWT using indicator function, the exact solution of a homogenous boundary value problem for Maxwell's equations is derived. A total number of six different complex constants are derived from a set of six boundary conditions for the proposed cold wave analysis. The presented theoretical analysis will be used in the design of the planar travelling wave tube amplifier (TWTA).
Citations
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25 Apr 2023
Abstract: A rectangular open tape helix is analysed for its dispersion characteristics by deriving the dispersion equations that restrict the fields within the tape helix region by incorporating a confinement function. The dispersion equations are derived by applying the accurate boundary conditions to one-quarter of the structure in axial and transverse directions owing to the symmetricity of the rectangular helical waveguide. The dispersion characteristics are numerically computed from an infinite number of simultaneous equations. The computed characteristics is compared with the theoretical model of sheath helix consisting of only the fundamental harmonics. Plotted dispersion characteristics reveals the potential usability of such devices as compact traveling wave tubes by miniaturization and can be printed.
25 Apr 2023
TL;DR: A rectangular open tape helix is analyzed in this article for its dispersion characteristics by deriving the dispersion equations that restrict the fields within the tape-helix region by incorporating a confinement function.
Abstract: A rectangular open tape helix is analysed for its dispersion characteristics by deriving the dispersion equations that restrict the fields within the tape helix region by incorporating a confinement function. The dispersion equations are derived by applying the accurate boundary conditions to one-quarter of the structure in axial and transverse directions owing to the symmetricity of the rectangular helical waveguide. The dispersion characteristics are numerically computed from an infinite number of simultaneous equations. The computed characteristics is compared with the theoretical model of sheath helix consisting of only the fundamental harmonics. Plotted dispersion characteristics reveals the potential usability of such devices as compact traveling wave tubes by miniaturization and can be printed.
References
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TL;DR: In this article, the authors investigated the properties of traveling wave-beam interaction in a rectangular helix traveling-wave-tube (TWT) for a solid sheet electron beam.
Abstract: This paper investigates the properties of traveling wave-beam interaction in a rectangular helix traveling-wave-tube (TWT) for a solid sheet electron beam. The ‘hot’ dispersion equation is obtained by means of the self-consistent fleld theory. The small signal analysis, which includes the efiects of the beam parameters and slow-wave structure (SWS) parameters, is carried out by theoretical computation. The numerical results show that the bandwidth and the smallsignal gain of the rectangular helix TWT increase as the beam current increases; and the beam voltage not obviously in∞uences the small signal gain. Among difierent rectangular helix structures, the small-signal gain increases as the width of the rectangular helix SWS increases, however, the bandwidth decreases whether structure parameters a and
8 citations
"Modified Dispersion Equation for Pl..." refers background in this paper
...Further, the structure has been considered anisotropically conducting and dimensionally symmetric with respect to all the axes[11]....
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20 Oct 2011
TL;DR: In this paper, the edge conditions for a perfect electrically conducting wedge in a medium with negative permittivity were investigated, and an optimization technique was used to solve the problem numerically.
Abstract: The work disclosed herein investigates the edge conditions for a perfect electrically conducting wedge in a medium with negative permittivity. A typical structure has been assumed in accordance with previous works for ordinary media, and an optimization technique has been used to solve the problem numerically. Special cases of importance have been explored mathematically.
5 citations
"Modified Dispersion Equation for Pl..." refers background in this paper
...Owing to the singularity of fields as per the Meixner’s Corner Conditions [14], and negligible dimensions of Region IV, its contribution to the fields has been ignored....
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TL;DR: Tape-helix analysis for determining the dispersion characteristics as well as the interaction impedance of a planar helix slow-wave structure with straight edge connections (PH-SEC) is presented in this paper.
Abstract: Tape-helix analysis for determining the dispersion characteristics as well as the interaction impedance of a planar helix slow-wave structure with straight edge connections (PH-SEC) is presented. The analysis is simplified by using the characteristic equation for an infinitely wide planar helix (PH) in free space and incorporating the effect of transverse confinement by straight-edge connections by applying the effective dielectric constant (EDC) method. It is shown that the results calculated from analytical expressions derived in this manner match well the simulation results obtained from CST in the frequency range far from cutoff. The EDC method is known to be inaccurate over the frequency range below cutoff. The simplified analysis is also used to determine the dispersion characteristics of a rectangular helix. The results based on the simplified analysis are shown to be more accurate than those from a previously reported complex tape-helix analysis of the rectangular helix.
5 citations