Анализ дисперсионных характеристик замедляющих систем, используемых в приборах терагерцового диапазона
In this paper the calculation of the dispersion characteristics of the slow-wave structures suitable for use in the terahertz range devices is conducted. The slow-wave structuress of the "winding waveguide"-, "serpentine"- and "counter-pins"-type can be considered as such. Analysis of the dispersion characteristics was carried out using waveguide-resonator model, which is built for slow-wave structures of the "winding waveguide"-type taking into account the channel for the electron beam. The waveguide-resonator model is composed of quadripoles describing the waveguide segments. This model is most accurately reflects the field structure in the "winding waveguide". The second approach is used to analyze the slowwave structures of "serpentine" and "counter-pins"-type. Analysis of the slow-wave structures was performed using the 3D-modelin in program HFSS . The dispersion characteristics were calculated by the program outlined in the work . These characteristics are used to build the model of the slow-wave structure, which is represented in this case by the chain of the octopoles of quadripoles. The discrete approach is the most common for the solution of this problems. Justification of the application of a mathematical model for the description of the discrete interaction follows from the difference form of electrodynamic excitation theory . Waveguide-resonator model is also used in the construction of a model of TWT section with the discrete interaction. High demands are made to the coefficients of the finite-difference equation, because the more accurately they are given, the more adequate the mathematical model of the discrete interaction in a relation to the physical laws. Those coefficients have a definite electrodynamic meaning and are defined via coefficients of the quadripole transmission matrix derived from the sextopole in the absence of the exciting current. This quadripole, in turn, is a mathematical model of the cell of the resonator slow-wave structure.