Innovations in Applied Physics

Topic and aim. The aim of the work is to consider an easy-to-implement system demonstrating the Smale–Williams hyperbolic attractor based on the Bonhoeffer–van der Pol oscillator, alternately manifesting a state of activity or suppression due to periodic modulation of the parameter by an external control signal, and supplemented with a delayed feedback circuit. Investigated models.

Topic. The paper is devoted to the study of mutual synchronization of two gyrotrons coupled with delay. As a rule, a theoretical study of synchronization of gyrotrons and other microwave oscillators is usually carried out by numerical simulations using certain well-established models of microwave electronics. Using this approach, it is difficult to provide a fairly complete synchronization pattern, using methods and ideas of nonlinear dynamics.

Topic. Investigation of nonlinear propagation modes of a spin-wave signal in lateral non-identical structures, taking into account the multi-mode spin waves. Aim. Consideration of the effect of intermode coupling on the intensity distribution of surface magnetostatic waves propagating in lateral waveguides of various widths.

Subject and purpose of the study. The paper presents the results of experimental studies of the effect of water vapor and light intensity on the conductivity of a thin film of tin dioxide at room temperature. It is known that the use of illumination of active layers of sensors allows to reduce their operating temperature, which expands the application field of sensors and multisensor systems based on them.

Subject of the study. Differentially coherent information transmission scheme using chaotic signals as carriers - DCSK (Differential Chaos Shift Keying) was proposed as an alternative to communication systems based on chaotic synchronization. It is resistant to noise and other disturbances at the same level as classic transmission systems based on regular signals.

We consider a layered multiferroic structure consists of laterally confined ferrite and ferroelectric layers. We study the influence of the air gap between the layers on properties of transverse modes of hybrid waves. By the solution of the electrodynamic problem with the finite element method we show that with increasing of distance between the ferrite and ferroelectric layer the coupling between the waves of these partial systems weakened.

The investigation of operation regimes of CW/263 GHz/1kW gyrotron, developed at IAP RAS/GYCOM Ltd., was made by various numerical methods. The influence of the azimuthal inhomogeneity (such as electron beam radial misalignments and tilt) has been studied. The method of average equations and 3D PIC codes (CST Studio Suite and KARAT) were used. Results, achieved by different methods, are in agreement with experimental data.

Выполнено проектирование экспериментального релятивистского гиротрона 3 мм диапазона длин волн с электронным пучком с энергией 250 кэВ с рекордными выходными параметрами (мощность генерации 5–10 МВт, КПД 35–40%, длительность СВЧ-импульса 0.5–1.0 мкс).

Topic and aim. The data on the latest achievements of authors on the development and investigation of field emitters for electron-beam microwave devices of millimeter and submillimeter wavelengths range are presented. Methods.

Aim of this work – to show the possibility of oscillation chaotization at the effect of low- frequency (0.1...3.0 MHz) noise signal both on feed circuit of IMPATT diode in one-frequency IMPATT diode oscillator (IMPATT-DO) and on feed circuit of transistor in one-frequency transistor oscillator.