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A new class of high-power klystrons, which use a dual frequency input and dual frequency bunching cavities, is proposed. This klystrons have both the efficiency about 90 % and the small bunching length. The global optimization procedure for the dual frequency klystron with the characteristics, suitable for modern colliders, was held. It was shown that the bunching process in such a klystron is very...
A new resonance device of the O-type, which was called resotrode with 2p-regeneration, is proposed. It contains 3-gaps input cavity with distance between the 1-st and the 3-ed gaps equals 2π. The device combines the advantages of the devices with modulated emission (IOT) and the advantages of the klystrons. Such a device has a high efficiency (90 % and greater), high gain (greater than 30 dB), small...
The surface and backward volume magnetostatic spin waves propagation in the side-coupled magnonic microwaveguides was numerically studied. The dispersion characteristics was calculated using the modification of finite element method. The transformation of the frequency dependence of the coupling length with the variation of the geometrical parameters was investigated. The cases of surface and backward...
In this work we report the experimental and numerical investigations of spin-electromagnetic waves propagating in finite-width multiferroic waveguide. Numerical simulation was provided by the developped finite-element method of electromagnetic eigenspectrum calculation. The control of electromagnetic spin wave spectra by the variation of dielectric permittivity was demonstrated. We show that the spatial...
The stationary (harmonic) excitation of the rectangular resonator with an absorbing dielectric layer on the lower wall several rectangular horns located on the top and side walls has been considered. With the end walls of the cavity it is possible the conveyor feed of dielectric product, for what is absorbing filter loaded with absorbers and prevent the exit of energy from the resonator. The filter...
The results of practical testing of previously proposed by the authors of the concept of constructing planar field emission structures based on the use of nanoscale diamond-like carbon film are presented. The complex of electrophysical and operational parameters of developed and manufactured multi-electrode cathode-grid assemblies is investigated — current-voltage characteristics; the level of average...
The work shows research of parasitic self-excitation of powerful cavity-type devices in static mode. Analysis program of parasitic self-excitation for multibeam klystron, traveling wave tube on a chain of coupled cavities and klystrons with distributed interaction is presented. A method of suppressing the parasitic self-excitation in the working range of accelerating voltages multibeam klystron is...
Modern development trend systems of wireless devices reconnaissance are to magnify operating frequency and expand bandwidth of radar impulses. Acousto-optic Bragg cells are commonly used as message entry device in such systems and thus entire system operation depends on its characteristics. Therefore enhancing performance of acousto-optic Bragg cells is a relevant objective. One the characteristics...
A wide band compact 20 dB directional coupler has been designed, fabricated and tested for high power operation within frequency band 4–12 GHz. In order to obtain broad band frequency response a three-section asymmetric coupled strip-line directional coupler has been chosen. Since the phase shift between the even and odd modes appears by their propagation through the strip-line discontinuities, a...
This report tells about researching of parametric generation in crossed fields. The main attention was preformed to interaction space formed by two coaxial cylinders with an axial magnetic field is a possible parametric generation of electromagnetic oscillations in the absence of the constant anode potential due to inhomogeneous magnetic induction components. Equations of motion were solved numerically...
This paper presents research results of electron gun characteristics with one and seven field-emission cells each of them contained autoemitter made of carbon glass in the form of needle with the high aspect ratio geometry and pulling grid separated from the cathode by the vacuum gap. In the pulse mode with the potential difference between the cathode and pulling grid 2813 V from the single tip with...
This report presents the results of calculation of electron-optical system consisting of a sheet CNT field emission cathode with a microgrid spaced from the surface of the emitter at 100 microns. On the basis of experimental data, it has been designed electron-optical system with a sheet CNT cathode with linear convergence of 6,25, and with the beam current density of 4,46 A/cm2. The thickness of...
Mutual phase locking of gyrotrons is important for power combining applications, especially for electron-cyclotron-resonance plasma heating. In this paper, a model of two coupled gyrotron oscillators is developed and basic properties of the phase locking are studied. Time delay of the coupling signal traveling between two gyrotrons strongly affects the pattern of phase-locking regimes. The model is...
This article is devoted to the research on a way to miniaturize a microstrip branch-line hybrid coupler. The construction miniaturizing is based on a simple bend of a micro strip line. This way is simple as it does not require complex mathematical calculations. During the process of design it was taken into account that compact devices should have similar characteristics to those of conventional constructions...
The paper presents the results of numerical simulation multi-tubular dual-frequency resonators for multi-beam klystrons working in Ka-band frequency with an output power level of the order a kilowatt at a cathode voltage of 4 kV. To improve efficiency in the output resonator implemented simultaneous adjustment of the resonator frequency of the first and third harmonics of the convection current (30...
Output parameters of TWT having waveguide outputs are calculated over the frequency range from 26 to 40 GHz. According to the proposed design of the interaction space, the absorber begins at once at the input of energy to provide the TWT stability to self-excitation at the cut-off frequency of the waveguide. It has such a frequency-dependent performance that the attenuation falls with a frequency...
Ion sources based on microwave discharge enables high ion beam currents due to the effective ionization of the microwave plasma. The analysis of different ion sources has shown that the creation of ion sources based on microwave plasma is quite realized technical task. Modeling and calculation of sources cavity resonators were carried out. The possibilities of using the rectangular cavity with oscillation...
Quasi-analytical technique of synonymous determination of wave impedance of equilateral hexagonal waveguide with homogeneous dielectric filling is proposed. Quasi-analytical calculation of wave impedance of hollow equilateral hexagonal waveguide for different values of normalized wavelength in free space is carried out on a basis of this technique.
Along with conventional dissipative dielectric materials, various 2D periodic structures, known as frequency selective surfaces or metasurfaces, are used today for absorbing electromagnetic waves in microwave and terahertz systems. Usually they are fabricated in the form of thin resistive elements periodically arranged on dielectric substrate. Metasurface absorber with cross shaped conducting elements...
Imaging spatially inhomogeneous acoustic fields is of considerable interest from the point of view of a various practical applications in the nondestructive examination, biomedicine and electronics. The most important task is to research new methods of imaging acoustic waves in a volume. The features of the imaging method of spatially inhomogeneous acoustic fields with a hybrid acousto-optical processor...
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