Superplačiajuosčių lėtinimo ir kreipimo sistemų modeliavimas ir analizė

Aim and tasks of the work. The aim of this work is to investigate insufficiently analyzed variants of the electrodynamic super-wide-band slow-wave structures, create their models, improve methods of analysis, analyze properties of the systems and reveal potentiality of the traveling-wave cathode-ray tubes, slow-wave structures. In order to achieve the aim it is necessary: 1. To improve method for evaluation of non-linear distortions in the traveling-wave cathode-ray tubes and reveal possibilities of reduction of non-linear distortions. 2. To create models of the insufficiently analyzed variants of slow-wave structures and reveal properties of the slow-wave structures. 3. To reveal influence of periodical non-homogeneities on properties of slow-wave structures, simulate and reveal influence of transitions to properties of slow-wave structures and traveling-wav cathode-ray tubes. 4. To make investigation of potentiality of slow-wave structures and traveling-wave cathode-ray tubes and select variants of slow-wave structures that can guarantee wide band and high operating speed of the traveling-wave cathode-ray tubes. Scientific novelty and practical value. Models of insufficiently simulated slow-wave structures were created and their properties were analyzed. According to analysis and modeling results, variants of systems were selected that can guarantee the wide pass-band and high operating speed of the traveling-wave cathode-ray tubes. Using finite element method calculation of characteristic impedances of multi-conductor line was improved and realized using Matlab PDE Tools software package. Methodology for calculation of pulse characteristics was suggested; calculation results and analysis were revealed. Influence of probe voltage step polarity, initial trajectory of electron beam, initial voltage shift and type of the system to configuration and rise time of pulse characteristic were revealed. The model of quasi-symmetrical deflection system was created and the dispersion equation was derived. Using the model, the influence of the short-circuited turns on retardation factor, input impedance of the quasi-symmetrical system and attenuation of the propagating wave in the system was considered. Characteristics of retardation factor, input impedance and attenuation versus frequency were calculated. The model of the twined helical deflection system was created and the dispersion equation was derived. Properties of the twined helical systems were revealed. Model of the twined helical system was improved after inner shield was inserted. Models of twined helical systems with inner shield were created, the dispersion equations were derived and their properties were revealed. Using the finite difference method, the electric field in the twined helical system was analyzed and compared with electric field of system that contains one helical. Models of the systems, containing periodical non-homogeneities, caused by the change of the helical wire width and dielectric holders were considered in order to reveal the influence of the non-homogeneities on properties of slow-wave structures at high frequencies. The dispersion equations were derived and characteristics of retardation factor and input impedance versus frequency were calculated. The super-wide-band electrical circuits, containing slow-wave structures, were considered in order to improve frequency and step responses of the circuits and electronic devices. The model of the circuit, containing elements, modeling the transitions between traveling-wave deflection systems and strip-lines, was proposed and the expressions for reflection coefficients and transfer functions were derived using the diagrams of multiple reflections. The calculated input impedance, amplitude frequency and step responses of the super-wide-band electrical circuits and traveling-wave tubes were presented and analyzed. Models of the gutter-type helical and serpentine structures, containing periodical non-homogeneities, caused by the window for the electron beam were considered and their properties were revealed. Calculation results of retardation factor, input impedance versus frequency were presented. Using the finite element method the electric field in the gutter-type systems was analyzed. Using software package CST Microwave Studio 3D models of the gutter-type helical systems were created. Calculation results of amplitude frequency characteristic, input impedance and delay time versus frequency were calculated. Methodology of research. Models of insufficiently analyzed slow-wave structures variants were created. Analytical multi-conductor line method was used for analysis. The numerical finite difference and finite element methods were used to increase accuracy of calculations of potential and electric field distribution, characteristic impedance. The numerical methods also were applied for solving of the dispersion equation, for calculations of electron trajectory and traveling-wave cathode-ray tubes characteristics, for analysis of linear and non-linear distortions. To supplement results, software package CST Microwave Studio was used. Obtained results were summarized and compared with results of other authors. Defended propositions: 1. Methods for analysis of deflecting electrical field, for evaluation of non-linear distortions in traveling-wave cathode-ray tubes, for calculation of step response of the traveling-wave cathode-ray tubes. 2. Methodology of analysis, models, the dispersion equations and analysis of results of quasi-symmetrical and twined helical slow-wave structures. 3. Models, the dispersion equations and analysis of results of non-homogeneous helical, serpentine, twined, quasi-symmetrical, and gutter type slow-wave structures. 4. Analysis of potentiality of the oscilloscope traveling-wave cathode-ray tubes and slow-wave structures. Conclusions: 1. Methodology for evaluation of influence of non-linear distortions on properties of the traveling-wave cathode-ray tubes was improved and possibilities to decrease non-linear distortions were revealed. 1.1 Non-linear distortions of signal image on the screen and the quality of the focusing of the electron beam can be decreased if symmetrical or gutter type deflection systems are used. 2. Models of insufficiently analyzed variants of slow-wave structures are created and their properties are revealed. 2.1 Short-circuited wires cause change of retardation factor and input impedance versus frequency of quasi-symmetrical system in the low frequency range. Loss in the short-circuited wires causes increase of attenuation in quasi-symmetrical system. Influence of the short-circuited wires as greater as resistance of wire greater and electromagnetic coupling between short-circuited wires and helical are greater. 2.2 Influence of the short-circuited wires on properties of quasi-symmetrical system is not very great, but can respond to assessment of traveling-wave cathode-ray tubes. 2.3 The pass-band of a system, containing twined helices with periodical change of the width of conductors, is limited to 1/4tD, where tD is the delay time of electromagnetic wave along the homogeneous section of a helical wire. Decrease of the periodic deviation of the helical wire width causes decrease of the retardation factor and less intensive change of the input impedance of the twinned helical system. 2.4 The strength of the deflecting field in the system, containing twined helices, strongly depends on the ratio of the widths of the neighbor helical wires. 2.5 It is possible to improve properties of twined helical system using inner shield: retardation factor and input impedance of the system changes with frequency less. 2.6 Input impedance of non-homogeneous gutter-type helical system with window for electron beam changes with frequency less than input impedance of homogeneous gutter-type helical system. Retardation factor of non-homogeneous gutter-type serpentine system changes with frequency less than retardation factor of homogeneous gutter-type serpentine system. 2.7 The strength of the deflecting electric field in the gutter-type systems changes with frequency less than in the helical and serpentine systems without the shields between the neighbor wires. 2.8 Amplitude-frequency response oscillations are caused by reflections, increasing with change of the system characteristic impedance – the characteristic impedance decreases with frequency. Relatively great non-uniformities of the responses are related to the resonant effects in the line, formed by the internal and external shields. When internal and external shields are short-circuited (when non-homogeneous gutter-type helical system is used) we can avoid resonant effects. 3. Influence of periodical non-homogeneities to properties of slow-wave structures is revealed, influence of transitions to properties of slow-wave structures and traveling-wav cathode-ray tubes is simulated and revealed. 3.1 The non-homogeneous helical, serpentine and gutter-type systems obtain properties of the rejection filter, when the phase difference angle between the voltages or currents on the neighbor helical wires approaches . 3.2 The width of the stop-band of the non-homogeneous helical system depends on the ratio of characteristic impedances of the homogeneous sections of the helical wire. 3.3 The width of the stop-band depends on the ratio of the capacitances, modeling non-homogeneities, and the distance between them. It is important that there is possibility to decrease and to move the stop-band to almost twice higher frequency range when mentioned ratios become 1. Period of the non-homogeneities determines location of the stop-band. It is possible to improve properties of the deflection systems using two or more uniform holders with the same distance between them instead of one. 3.4 The dimensions of the gap for electron beam in the non-homogeneous gutter-type systems must be minimal. 3.5 Transitions of the defle.