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Information × Registration Number 0212U002689, 0109U000541 , R & D reports Title The investigation of impulse propagation and radiation in open and conical waveguides and waveguides with dispersion medium popup.stage_title Head Kolchigin Mikola, Bytrim Oleksandr, Registration Date 26-01-2012 Organization Kharkov National University named after V.N. Karazin popup.description2 Object of the research is the process of propagation of arbitrary transient signals in several waveguiding structures and radiation of such signals in these structures. Aim of the work is to develop new analytic methods for analysis of pulse propagation in different waveguides, diffraction at the open ends of such waveguides, to develop on their base series of mathematical models of pulse radiators. This research is a continuation of the research and development studies conducted at the chair of theo-retical radiophysics of Kharkov National University during 2006-2008. The subject of the study is the process of transient electromagnetic waves propagation and ra-diation. The method of studying is based on several new computation methods that were advanced from mode basis method. In particular an open waveguide was considered. A peculiarity of such a waveguide is the presence of continuous spectrum of modes. Also the known earlier mode matching technique was first applied to solving the diffraction problems directly in the time domain. A system of evolutionary waveguide equations for the waveguide with biisotropic medium was derived as well. In the study the formulae are derived for expansion of the full electromagnetic field on the continu-ous spectrum of the mode basis, which is built in a closed form for a circular dielectric waveguide. Excita-tion and propagation of a pulse wave along the dielectric waveguide was studied. In particular a new effect was revealed that consists in propagation of a pulse surface wave with a speed of light in the outer medium (air), and the effect of creation of Cherenkov type cone radiation into the waveguide by such a wave. This cone forms a precursor on the waveguide axis that propagates along the waveguide with the same speed of light in the air. Besides the problem of radiation of pulse signals by open ends of a regular conical waveguides was considered. The model of radiation was built on the base of uniting the mode matching technique, which was first applied in the time domain, with the mode basis method that was used for cal-culation of independent wave propagation in the regular parts of the radiating structure. MODE BASIS METHOD, BIISOTROPIC MEDIUM, PULSE SIGNALS, PULSE ANTENNA, DI-ELECTRIC WAVEGUIDE, PRECURSOR. Product Description popup.authors Кочетов Б. Легонький М. Хе Ши popup.nrat_date 2020-04-02 Close