Study Of Beam Wave Interaction Nonlinear Theory For Traveling Wave Tube

Traveling-wave Tubes (TWTs) are high power microwave amplifiers which arewidely used in vacuum radar transmitters, electronic interference equipments,communicating satellites and so on. TWTs are modern military electronic essentialmicrowave amplifiers, therefore modern military electronic application gives TWTshigher and higher index claimation. Demands of improving interaction, reducingharmonic output, reducing noise and suppressing oscillations and so on are growing,especially for communicate satellites which give strictly linearization index claimation.Beam wave interaction (BWI) is the most critical part in a TWT. A TWT isworking by the system that electron beam and high frequency field interacting duringtheir way of transferring the electronic kinetic energy to high frequency field energy. Inthe TWT BWI process, high speed electronic energy is given to the high frequencyeletromagnetic field. The high frequency field can be divided into the forward field partand reverse field part. The electrons will be accelerated by forward field or sloweddown by reverse field. As the difference of electron locations, some electrons areaccelerated while other electrons are slowed down. This explains the electrons’ groupgathering. If the group gathering center is in the slow down scale, most electrons are inslow down scale, so the electrons will lose more energy while obtain fewer energy, thisis the excitation and enlargement of the high frequency field.Euler linear theory is BWI theory which is established in Euler coordinate system.This article about the Euler nonlinear BWI theory, developed from the established Eulerlinear theory, can be used to describe abnormal dispersion suppression and the harmonicstudy. The linear situation’s fundamental wave relatively phase angle are divided by thefundamental wave phase speed’s relationship and two order harmonic’s relatively phaseangle with fundamental wave phase speed’s relationship. According to the simulationgraphs, it can be seen that the fundamental wave’s relatively phase angle graduallyimprove while the phase speed gradually drops. So it is said that the abnormaldispersion can be used in both the improvement of the fundamental wave’s power andthe suppression of the harmonic power. Euler nonlinear theory is developed according to the differences between thenonlinear theories and linear theories. On getting nonlinear theory’s dynamic equationsand field equations, and according to Euler linear theory’s analytical solutions, the Eulernonlinear BWI theory can be described by the iterations of dynamic equations and fieldequations. On obtaining the nonlinear equation’s initial analytical solution, the finalsolution of the BWI parameters, such as the field amplitude, phase shift, output power,relatively phase angle can be simulated. The establishment of Euler nonlinear theoryplatform is proven by giving the figures of output parameters, such as output power andthe field amplitude.