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436 Simulation and application of the super-wide pass-band slow-wave structuresAs a result of performed investigations, new fields for application of slowwavedevices were discovered. At the same time, requirements for special propertiesof the devices appeared.The slow-wave devices with the super-wide pass-band are necessary forelectromagnetic delay lines (DL) and traveling-wave cathode-ray tubes(TW CRT). TW CRTs are developed for traveling-wave oscilloscopes that areused for investigation of single high-speed processes. Traveling-wave deflectionsystems must ensure the pass-band of tubes and oscilloscopes from 0 to somegigahertz.In 1965, professor Zenonas Vainoris initiated research in the field of electrodynamicslow-wave devices at Vilnius Gediminas Technical University. As aresult of research in the period 1965–95, important problems, related to investigationand design of the super-wide band delay lines and traveling-wave deflectingsystems, are solved. The generalized theory of super-wide band helical andmeander systems is developed. Processes in traveling-wave deflecting systemsare revealed, and theory of TW CRTs is developed. New technical solutions inthe field of the super-wide band delay lines and traveling-wave deflecting systemsare proposed. The main results of investigations are presented in [6–9].Approximately from 1990, intensive investigations in the field of electromagneticsbegan. They were based on wide application of numerical methods forinvestigation of electromagnetic fields, microwave and other electrodynamic devices.The main problems and their solutions are discovered in [10–14] and otheroverviewing works.The principles of numerical methods are described in [15–27].Numerical methods are used for solution of Maxwell, Poisson and Laplaceequations. Differential and integral forms of Maxwell equations are used. For thisreason, two groups of numerical methods are developed. Methods of the firstgroup are based on solution of differential equations with partial derivatives. Finitedifference method (FDM), finite element method (FEM), and finite differencetime domain method (FDTD) are the methods of this group. Methods of the othergroup (integral equation methods) are used for solution of integral equations. Themost important method of this group is the method of moments (MoM).Besides mentioned methods, new modifications of numerical methods aredeveloped. On the basis of FDTD and MoM, the very effective finite integrationmethod (FIM) is created. It is used for software systems MAFIA and MicroWaveSudio developed by Computer Simulation Technology (CST) Company for analysisof electromagnetic fields, simulation and design of microwave devices.Authors of this monograph used electrodynamic, multiconductor line andnumerical methods for modeling, simulation, analysis and design of super-wideband slow-wave structures.