فهرس المقالات Traveling wave tube

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  1 - Plasma effect in tape helix traveling-wave tube
  S. Saviz F. Salehizadeh
  10.1007/s40094-014-0125-9
  AbstractA linearized relativistic field theory of a plasma-loaded helix traveling-wave tube is presented for a configuration where a solid electron beam propagate through a sheath helix enclosed within a loss-free wall in which the gap between the helix and the outer wa أکثر

  AbstractA linearized relativistic field theory of a plasma-loaded helix traveling-wave tube is presented for a configuration where a solid electron beam propagate through a sheath helix enclosed within a loss-free wall in which the gap between the helix and the outer wall is filled with a dielectric. Numerical study of the effect of plasma density on the phase velocity and growth rate has been done. Numerical results show that the plasma have different behaviors in different density limits. تفاصيل المقالة
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  2 - The effect of beam and plasma parameters on the four modes of plasma-loaded traveling-wave tube with tape helix
  S. Saviz
  10.1007/s40094-014-0135-7
  AbstractField theory is applied to analyze the behavior of the electromagnetic wave in the presence of a solid electron beam and magnetized plasma-loaded tape helix traveling-wave tube. The obtained dispersion relation implicitly includes azimuthal variations and all sp أکثر

  AbstractField theory is applied to analyze the behavior of the electromagnetic wave in the presence of a solid electron beam and magnetized plasma-loaded tape helix traveling-wave tube. The obtained dispersion relation implicitly includes azimuthal variations and all spatial harmonics of the tape helix. Results indicate that the frequency and the phase velocity of (Xbp − Xp) and (Obp − Xp) modes increase with cyclotron frequency and for (Obp − Op) and (Xbp − Op) modes decrease. In the strong magnetic field limit, the maximum growth rate and frequency of all modes are constant at different values of cyclotron frequency and beam energy. If the plasma density increases, the frequency and phase velocity of four modes will increase. The maximum growth rates of the four modes in the lower plasma density are equal and for higher values of plasma density the (Obp − Xp) mode has greatest value. The phase velocity and the frequency of (Xbp − Xp) with (Xbp − Op) modes and (Obp − Op) with (Obp − Xp) modes are coinciding with each other and for first case increase with beam density, but for latter decrease. The maximum growth rate of (Obp − Op) mode and the maximum frequency of (Xbp − Xp) mode have highest values as a function of the electron beam density. تفاصيل المقالة
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  3 - Nonlinear study of injection process types into the traveling wave tube with hollow electron beam
  H. Bayati S. Saviz A. H. Sari
  10.1007/s40094-019-0327-2
  AbstractIn this paper, examples of all types of signal injection such as different signal , harmonic signal and multiple signal injections in a TWT including hollow electron beam near frequency 1800 MHz and within input powers lower than TWT saturation power has been an أکثر

  AbstractIn this paper, examples of all types of signal injection such as different signal , harmonic signal and multiple signal injections in a TWT including hollow electron beam near frequency 1800 MHz and within input powers lower than TWT saturation power has been analyzed using approximate analytical solution of S-MUSE model. Later, the results obtained from approximate analytical solution with large signal code LATTE, that is a Lagrangian model, have been tested and simulated so that the effect of input phase difference between drive and injected wave and the effect of input powers on the amplification value of drive and generated second-order harmonic waves were investigated. The phase difference between drive and harmonic waves is a key parameter in harmonic injection for increasing the output power of drive and second-order harmonic frequencies. تفاصيل المقالة
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  4 - Investigating variations of the electron beam voltage on the traveling wave tube output power in the different frequencies
  F. Sheykhe Sh. Saviz M. Salem
  10.1007/s40094-018-0292-1
  AbstractIn the present research, the effect of variations of the electron beam voltage on the output power is studied. In order to develop the study, this problem was investigated at different frequencies, which are the products of nonlinear behavior of the traveling wa أکثر

  AbstractIn the present research, the effect of variations of the electron beam voltage on the output power is studied. In order to develop the study, this problem was investigated at different frequencies, which are the products of nonlinear behavior of the traveling wave tube (TWT) in response to the input frequency. Moreover, for a more realistic understanding, the tubes were considered with two linear and nonlinear responses to the input frequency. The TWT output power was calculated in linear and nonlinear modes, at different frequencies using the numerical solution of the mathematical equations of the Lagrangian model. Then, the output power in terms of distance and beam voltage in different frequencies was plotted and compared. The results revealed that the effects of variations of voltage on the output power were more proper in a single-mode TWT in comparison with a multimode one. تفاصيل المقالة
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  5 - The new wave-ring helical (WRH) slow-wave structure for traveling wave tube amplifiers
  Nasser Panahi S. Saviz M. Ghorannevis
  10.1007/s40094-017-0266-8
  AbstractIn this paper, the new slow-wave structure called wave-ring helix to enhance the power of the traveling wave tubes is introduced. In this new structure, without increasing the length and radius of the helix, the wave motion path can be increased to radiofrequenc أکثر

  AbstractIn this paper, the new slow-wave structure called wave-ring helix to enhance the power of the traveling wave tubes is introduced. In this new structure, without increasing the length and radius of the helix, the wave motion path can be increased to radiofrequency wave in phase with the electron beam. The results show that in the special frequency range the output power and gain are greater than conventional helix. In this paper, optimization results are presented in cold and hot tests on the new structure. The software CST is used in S-band frequency range. تفاصيل المقالة