Evaluation of vortex fields in a non-linear slow-wave structure. I. The method of instantaneous values

The "spectral" technique of microwave tubes simulation allows obtaining frequency dependencies of various tube parameters in wide frequency continuum up to whole delay line passband. It based on transformation of input signal from frequency domain to time one and using it as a boundary condition of the non-stationary model. During the numerical simulation of wave propagation through a non-linear slow-wave structure, the output signal and other tube parameters (e.g. electrode currents) are transferred back to frequency domain and periodically plotted on monitor screen in exactly the same way as on a spectrum analyzer.