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Ustinov A.B.,St Petersburg Electrotechnical University | Kalinikos B.A.,St Petersburg Electrotechnical University | Srinivasan G.,Oakland University
Applied Physics Letters | Year: 2014

A nonlinear microwave phase shifter based on a planar multiferroic composite has been studied. The multiferroic structure is fabricated in the form of a bilayer consisting of yttrium iron garnet and barium strontium titanate. The principle of operation of the device is based on the linear and nonlinear control of the phase shift of the hybrid spin-electromagnetic waves propagating in the bilayer. The linear control is realized with magnetic and electric fields. The nonlinear control is provided by the input power of microwave signal. The device showed a nonlinear phase shift up to 250°, electric field induced phase shift up to 330°, and magnetic field induced phase shift of more than 180°. © 2014 AIP Publishing LLC.


Demidovich V.B.,St Petersburg Electrotechnical University | Rastvorova I.I.,St. Petersburg State Mining Institute
Russian Electrical Engineering | Year: 2014

A combined method for numerical computation of the electromagnetic field in induction-heating systems is proposed and used. The method consists in a combination of methods of integral equations for the computation of the electromagnetic field in the area outside the load and methods of finite elements or finite differences for the computation of the electromagnetic field inside the load. A method of simulation of electrotechnical systems with simultaneous solving of circuit and field problems is proposed based on this method. Using the example of induction-heating devices, an external problem associated with the computation of circuit inductors, power supplies, and balancing capacitors and an internal problem related to the computation of the electromagnetic field and internal heat sources inside the load are formulated. The simulation of induction heaters is considered taking into account features of thyristor frequency converters with a parallel inverter. © 2014, Allerton Press, Inc.


Tong W.,Colorado State University | Tong W.,Chinese Academy of Sciences | Wu M.,Colorado State University | Carr L.D.,Colorado School of Mines | Kalinikos B.A.,St Petersburg Electrotechnical University
Physical Review Letters | Year: 2010

This Letter reports experimental results on random temporal dark solitons. One excites an incoherent large-amplitude propagating spin-wave packet in a ferromagnetic film strip with a repulsive, instantaneous nonlinearity. One then observes the random formation of dark solitons from this wave packet. The solitons appear randomly in time and in position relative to the entire wave packet. They can be gray or black. In spite of the randomness of the initial wave packets and the random formation processes, the solitons show signatures that are found for conventional coherent dark solitons. © 2010 The American Physical Society.


Machac J.,Czech Technical University | Polivka M.,Czech Technical University | Zemlyakov K.,St Petersburg Electrotechnical University
IEEE Transactions on Antennas and Propagation | Year: 2013

This communication presents the results of an investigation of a new version of a leaky wave antenna designed on a CRLH substrate integrated waveguide. The antenna operates in two frequency bands and its main beam can be steered from backward to forward direction by changing the frequency. The antenna structure is planar and can be fabricated by a standard PCB technology, so it is suitable for mass production. An efficient method for determining the complex dispersion characteristic of periodic 1D structure is proposed. © 1963-2012 IEEE.


Belorus A.O.,St Petersburg Electrotechnical University | Maraeva E.V.,St Petersburg Electrotechnical University | Spivak Y.M.,St Petersburg Electrotechnical University | Moshnikov V.A.,Polytechnic University of Mozambique
Journal of Physics: Conference Series | Year: 2015

Gas adsorption and capillary condensation phenomena were studied in powders of porous silicon with different doping levels of the silicon substrate of n-type conductivity in various conditions. Specific surface area and the rated pore size distribution were determined for porous silicon with complex texture by the capillary condensation method. It is shown that the samples obtained in silicon with a higher doping level have a higher value of specific surface area. © Published under licence by IOP Publishing Ltd.


Ustinov A.B.,St Petersburg Electrotechnical University | Drozdovskii A.V.,St Petersburg Electrotechnical University | Kalinikos B.A.,St Petersburg Electrotechnical University
Applied Physics Letters | Year: 2010

A multifunctional microwave spin-wave device utilizing a ferrite-film magnonic crystal is reported. A principal of operation of the device is based on a nonlinear frequency shift and a nonlinear damping of the carrier spin waves propagating in the magnonic crystal. The device performs several functions of microwave signal processing, namely, enhancement of signal-to-noise ratio, limiting or suppression of high-power signals, and power-dependent phase shift. © 2010 American Institute of Physics.


Ustinov A.B.,St Petersburg Electrotechnical University | Kalinikos B.A.,St Petersburg Electrotechnical University | Demidov V.E.,University of Munster | Demokritov S.O.,University of Munster
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We have studied experimentally the formation of magnetic solitons in a periodic system constituted by a ferromagnetic film and a periodic metal grating. We show that due to the finite-size effects and the influence of dynamic magnetic losses, the wave dispersion within the stop bands caused by the periodicity allows observation of both bright and dark solitons formed via the induced and the coupled modulation instabilities. We find that the flexibility of the studied system enables a wide variation in the characteristics of the excited solitons by the proper choice of the experimental conditions. © 2010 The American Physical Society.


Ustinov A.B.,St Petersburg Electrotechnical University | Kondrashov A.V.,St Petersburg Electrotechnical University | Nikitin A.A.,St Petersburg Electrotechnical University | Kalinikos B.A.,St Petersburg Electrotechnical University
Applied Physics Letters | Year: 2014

Self-generation of microwave spin-electromagnetic wave envelope solitons and chaos has been observed and studied. For the investigation, we used a feedback active ring oscillator based on artificial multiferroic, which served as a nonlinear waveguide. We show that by increasing the wave amplification in the feedback ring circuit, a transition from monochromatic auto-generation to soliton train waveform and then to dynamical chaos occurs in accordance with the Ruelle-Takens scenario. Management of spin-electromagnetic-wave solitons and chaos parameters by both dielectric permittivity and magnetic permeability of the multiferroic waveguiding structure is demonstrated. © 2014 AIP Publishing LLC.


Ustinov A.B.,St Petersburg Electrotechnical University | Demidov V.E.,University of Munster | Kondrashov A.V.,St Petersburg Electrotechnical University | Kalinikos B.A.,St Petersburg Electrotechnical University | Demokritov S.O.,University of Munster
Physical Review Letters | Year: 2011

The transition from stationary to chaotic spin-wave soliton trains has been observed. The experiment utilized cw excitation of envelope solitons through self-modulation instability of spin waves. By increasing the spin-wave power, the secondary self-modulation instability succeeded the primary modulation instability, resulting in after-modulation of the soliton train amplitude. Further increase of the spin-wave power led to development of the higher-order instabilities, resulting in formation of the chaotic soliton train. © 2011 The American Physical Society.


Mukhin N.V.,St Petersburg Electrotechnical University
Glass Physics and Chemistry | Year: 2014

A one-dimensional model describing the diffusion of intrinsic defects in lead zirconate titanate (LZT) films of nonstoichiometric composition during their high-temperature treatment is proposed. The model includes the diffusion of vacancies by lead and oxygen, the formation and decay of their associates, interaction with extensive defects (dislocations in LZT films and the near-surface layer), interstitial inclusions, and LZT film contact with air leading to lead oxide evaporation from LZT film and its saturation by oxygen. The dependences of LZT film composition on the temperature and time of treatment are calculated. The possibility the concentration's oversaturation by lead in a near-surface layer of LZT film, which can lead to the release of lead oxide, is shown. © 2014 Pleiades Publishing, Ltd.

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