A linear theory model is developed to analyze gyrotron traveling wave tubes ~gyro-TWT! employing nonuniform interaction structures, which can be tapered wall waveguide, severed tubes, or distributed lossy wall waveguides. Effects of the wall loss, reflections caused by the nonuniformity of the waveguide, and beam–wave interactions inside the sever region are incorporated in this theory. In addi...

Nowadays, piezoelectric materials have wide applications in various industries. Therefore, investigation of these materials and their applications has a special importance. In this paper first, the natural frequencies of a traveling-wave piezoelectric motor are achieved, using finite elements simulations. Then, applying an alternative electrical voltage to the piezoelectric ring, a traveling wa...

the homogeneous balance method can be used to construct exact traveling wave solutions of nonlinear partial differential equations. in this paper, this method is used to construct newsoliton solutions of the (3+1) jimbo--miwa equation.

Traveling Wave Tubes (TWTs) consist of different elements. The most important element of TWT is the RF circuit. RF circuits in helix TWTs need a dielectric support to hold the helix; this support also has an effect in electromagnetic properties of RF circuits. A novel dielectric support is proposed to reduce the second harmonic of helix TWTs. The dielectric support in this structure consists of...

We study propulsion of micro-swimmers in 3D creeping flow. The swimmers are assumed to be made of elastic cylindrical hollow tubes. The swimming is generated by the contractions of the tube’s elastic membrane walls producing a traveling wave in the form of a “step-function” traversing the swimmer from right to left, propelling the swimmer from left to right. The problem is motivated by medical ...

Meander lines are promising slow-wave structures (SWSs) for millimeter-wave traveling-wave tubes (TWTs) due to low-cost manufacture, low-voltage operation, and high interaction impedance. However, experimental results on meander rare in the literature. Phase velocity impedance most important parameters design characterization of TWT SWSs. Their determination is crucial validating simulations de...

In this article, an improved model for the beam-wave interaction of sheet beam in traveling wave tubes (TWTs) considering ohmic losses and reflections is presented. The are obtained by field analysis equivalent method. space charge magnetic derived from active Helmholtz's equation. An algorithm to obtain S-matrix circuit method relativistic Boris applied accelerate macroparticles. exchanged pow...

In this paper, the coupled dispersive (2+1)-dimensional long wave equation is studied. The traveling wave hypothesis yields complexiton solutions. Subsequently, the wave equation is studied with power law nonlinearity where the ansatz method is applied to yield solitary wave solutions. The constraint conditions for the existence of solitons naturally fall out of the derivation of the soliton so...

in this paper, the coupled dispersive (2+1)-dimensional long wave equation is studied. the traveling wave hypothesis yields complexiton solutions. subsequently, the wave equation is studied with power law nonlinearity where the ansatz method is applied to yield solitary wave solutions. the constraint conditions for the existence of solitons naturally fall out of the derivation of the soliton so...