ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)

Innovations in applied physics

Generation of chaotic wide-band impulses in uhf range by twt autogenerator

This work presents results of experimental research of chaotic signal wide-band generator based on UHF band TWT amplifier. Two generation methods of chaotic pulses sequences were investigated.

Theory of pregeneration mode in bwo in the frame of two-dimensional model

Processes in backward wave oscillator in pregeneration mode have been considered in the frame of two-dimensional theory. Spectral density dependencies on the relative transit angle are presented. The influence of magnetic field and space charge on its behavior has been analyzed.

About consideration of electron transverse motions in resistive wall amplifier

Resistive wall amplifier is a vacuum microwave device, which has not been spread, but attracts attention again. Main features – no need to slow-wave structure and almost complete lack of feedback between output and input. The amplification occurs due to the phase shift between the electron beam and field variables that arise due to the presence of absorbing walls. The classic version of this device has high values of gain, however, if you replace the usual coating of a dielectric for metamaterial, gain increases substantially.

Numerical simulation of electron-beam «squeezed» state in purpose to study the possibility of effective plasma frequency increase

Three-dimensional electromagnetic numerical simulation is carried out of «squeezed» state of the electron beam in two-section vircator system with drift tubes of different diameters. We have studied the influence of two-section system geometric parameters on the nonlinear dynamics of electron beam. We have obtained an effective plasma frequency depending on the system parameters.

Current-less tuning and control of self-oscillations frequency terahertz range klynotron

Terahertz-range backward wave oscillator – carcinotrons and klynotrons are widely used in radioelectronics systems for solving fundamental and applied problems. Instability of the output signal frequency of the said lamps is not worse than 10?4. The frequency of the carcinotron and klynotron output signal as a rule carried out by changing the operating voltage, i.e. with the expenditure of energy in the control circuit.

Investigation of possibility to use ion treatment for enhancement of gyrotron cathode quality

A method for gyrotron cathode treatment by flow of potassium ions has been developed, and the effect of ion bombardment on the emission characteristics of W-Ba and LaB6 cathodes has been investigated. The influence of cathode surface material, cathode emission activity and ion energy on the result of ion treatment was revealed.

Relativistic magnetrons’ development stages

A paper presents the main stages of relativistic magnetrons’ development. We describe the designs eliminating conventional magnetrons’ shortcomings and restrictions which are associated with a radial output of radiation through a narrow slot in one of the magnetron resonators. A low breakdown threshold and an operation in only nondegenerate modes are among these restrictions.

Gyrotron frequency stabilization under the influence of external monochromatic signal or wave reflected from the load: review

We study gyrotron frequency locking by the external monochromatic wave and stabilization of gyrotron frequency by the wave reflected from the non-resonant or resonant load. Although in the last decades influence of the external monochromatic signal and the reflected wave at the gyrotron operation was studied in a number of publications, concrete schemes of gyrotron frequency stabilization weren’t discussed.

Influence of input signal power on magnetostatic surface waves propagation in yttrium-iron garnet films on silicon substrates

Yttrium iron garnet (YIG) films on silicon substrates (Si) are of a great interest due to compatibility of their fabrication with semiconductor technologies and, thus, possible integration of magnonic and electronic devices on one chip. However, features of spin wave propagation in YIG films on semiconductor substrates remain almost unexplored.

Influence of parametric instability of magnetostatic surface spin waves on formation of defect modes in one-dimensional magnonic crystal with defect

Propagation of nonlinear magnetostatic surface waves through the one-dimensional magnonic crystal based on yttrium-iron garnet film with the defect of periodic array was experimentally studied. Interest in the study of the magnonic crystals with defects is caused by the possibility of exciting of defect modes inside the forbidden gaps of MSSW spectrum that can be used to enhance the non-linear effects and signals control in the microwave range.