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1.
We have experimentally studied specific features of the generation of chaotic microwave pulse trains in a self-oscillating
ring system with nonlinear delay line on surface magnetostatic waves, bandpass filter, and power amplifier on GaAs field-effect
transistors under the action of an external pulse-modulated microwave signal occurring outside the band of the generated chaotic
signal. It is established that a decrease in the off/duty ratio in the external pulse-modulated microwave signal leads to
an increase in this ratio for the chaotic microwave pulses. The integral power of the chaotic microwave signal generated under
the pulsed external signal action is increased as compared to the power of signal generated in the autonomous regime. 相似文献
2.
S. V. Grishin S. A. Nikitov D. V. Romanenko V. O. Khudolozhkin Yu. P. Sharaevskii 《Technical Physics Letters》2013,39(4):321-324
The generation of single chaotic microwave pulses in a self-oscillating ring system with ferromagnetic film under the action of external narrow-band noise microwave signal occurring outside the band of frequencies of the chaotic microwave signal was observed. Chaotic generation emerged due to the parametric instability of the magnetostatic surface wave in the ferromagnetic film, whereas formation of single chaotic microwave pulses was caused by the absence of complete suppression of chaos under the action of narrowband noise. 相似文献
3.
Grishin S. V. Dmitriev B. S. Zharkov Yu. D. Skorokhodov V. N. Sharaevskii Yu. P. 《Technical Physics Letters》2010,36(1):76-79
The autonomous generation of stationary chaotic microwave pulse trains in a self-oscillating ring system with a multicavity
klystron power amplifier operating in a small-signal regime and a wideband non-linear delay line on surface magnetostatic
waves has been experimentally studied. It is established that the characteristics of generated chaotic microwave pulses can
be controlled by varying the electron beam current and accelerating voltage in the klystron. 相似文献
4.
A quasi-periodic sequence of pulses in a self-oscillating ring system with a resonant amplifier and a ferromagnetic film has been generated upon three-wave parametric interaction of spin waves. It is established that the generated pulses are analogs of dissipative bright solitons, which are formed as a result of competition between amplification and loss, as well as between time dispersion and nonlinearity. To describe the mechanism of formation of these structures, we have proposed a model in the form of three parametrically coupled differential equations with amplification and a differential equation of linear oscillator. Under certain assumptions, this model has analytical solutions in time in the form of structures with a profile similar to that of bright solitons. 相似文献
5.
V. S. Anishchenko A. B. Neiman A. N. Silchenko I. A. Khovanov 《Dynamical Systems: An International Journal》1999,14(3):211-231
We study synchronization of switching processes in stochastic and chaotic bistable systems driven by a periodic signal in terms of phase synchronization. By introduction of instantaneous phases of transitions between metastable states and of the periodic forcing we show explicitly the effect of phase locking. The dynamics of phase difference appears to be qualitatively equivalent to that of a synchronized classical self-sustained oscillator. We have found that the degree of phase coherence between the input signal and the response estimated employing the effective diffusion constant is maximal at an optimal noise level in a stochastic bistable system or at an optimal value of a control parameter in a purely deterministic case. We also consider the effect of mutual synchronization of the switching processes in coupled stochastic and chaotic bistable systems. 相似文献
6.
Beginin E. N. Grishin S. V. Nikitov S. A. Sharaevskii Yu. P. Sheshukova S. E. 《Technical Physics Letters》2011,37(11):1065-1069
Generation of chaotic dissipative solitons has been observed in an active ring resonator with one-dimensional periodic ferromagnetic
microstructure comprising a single-crystalline film of yttrium iron garnet (YIG) with a lattice of grooves oriented perpendicular
to the direction of propagation of a magnetostatic surface wave (MSSW). A quasi-periodic train of chaotic dissipative solitons
was generated in this system under the conditions of three-magnon processes of MSSW decay due to the passive synchronization
(PS) of spin wave self-modulation in a frequency band corresponding to the first bandgap. The PS onset was caused by the saturable
absorption of microwave signals within the bandgap of the MSSW transmission line. 相似文献
7.
We consider the time required for complete synchronization of two identical one-way coupled van der Pol-Duffing oscillators
occurring in the regime of dynamic chaos. The influence of the initial phase difference between oscillators on the duration
of the process of complete synchronization has been studied. At a fixed phase of chaotic oscillations of the self-excited
drive oscillator, the period of time (past the coupling onset) during which the complete synchronization regime is established
depends on the phase of the self-excited response oscillator. 相似文献
8.
9.
E. N. Beginin S. V. Grishin M. A. Morozova Yu. P. Sharaevskii 《Technical Physics Letters》2009,35(9):853-856
Various regimes of chaotic signal generation have been studied in an self-oscillating ring system with a wideband nonlinear
delay line based on coupled ferromagnetic films, in which magnetostatic backward volume waves (MSBVWs) are excited. It is
shown for the first time that the simultaneous excitation of two waves in the coupled films leads to the appearance of a falling
part in the dynamic characteristic of the MSBVW delay line and the generation of a broadband chaotic signal with a continuous
spectrum. Under certain conditions, the ring exhibits a regime of intermittency, in which broadband chaotic signals with both
continuous and discrete spectra are generated. 相似文献
10.
It is shown that a periodic series of ultrashort pulses can be formed in electron microwave generators with a bleachable absorber in the feedback loop. The peak power of such radiation is considerably higher than radiation power in stationary modes. The pulsed generation method is analogous to the method of passive synchronization of waves, which is widely used in laser physics. 相似文献
11.
A. M. Zyuzin S. N. Sabaev A. G. Bazhanov V. V. Radaikin 《Technical Physics Letters》2001,27(2):147-149
The spin wave resonance band intensity in two-layer film structures exhibits an anomalous variation. The experimental data and the results of model calculations indicate that a mechanism responsible for the resonance band intensity increase with the mode number is related to the presence of a spin wave decay region in the pinning layer. 相似文献
12.
A new quasi-three-dimensional method of moments (Quasi-3-D MoM) for analyzing electromagnetic wave scattering from a cylindrical dielectric object surrounded by a dipole array in microwave tomography systems is presented in this paper. A wire-volumetric electric field integral equation is derived for the electromagnetic wave scattering phenomena in microwave tomography systems. The new method is based on the MoM and involves rectangular cylindrical cells modeling the cylindrical object. The distribution of electric flux densities along the axial direction of cylindrical cells is expanded as a Fourier series multiplied by an attenuation factor, which is one part of basis functions. Therefore, the Quasi-3-D MoM is performed in a two-dimensional discretization, and the computational complexity is reduced. Detailed mathematical steps along with some numerical results are presented to illustrate the efficacy and accuracy of this approach. 相似文献
13.
A. V. Kozlov A. G. Shashkov A. S. Trofimov 《Journal of Engineering Physics and Thermophysics》1991,61(1):922-926
An effective method has been developed to determine thermophysical properties of materials from the available thermophysical measurements.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 61, No. 1, pp. 141–145, July, 1991. 相似文献
14.
A. A. Ovchinnikov O. I. Moskalenko A. A. Koronovskiĭ A. E. Hramov 《Technical Physics Letters》2010,36(2):148-150
The influence of an external source of noise on the position of the boundary of generalized synchronization (GS) of two unidirectionally
coupled chaotic oscillators has been experimentally studied for the first time. It is established that the GS threshold remains
unchanged in a broad range of the external noise intensity, i.e., the GS regime is stable with respect to external noise. 相似文献
15.
O. I. Moskalenko 《Technical Physics Letters》2007,33(10):841-843
Intermittent behavior has been studied near the boundary of phase synchronization in an autooscillatory system with periodic dynamics under the action of an external chaotic signal. It is shown that the intermittency obeys the same scenario as that observed in the case of interaction between two coupled chaotic oscillators. 相似文献
16.
V. A. Avgustinovich S. N. Artemenko V. S. Igumnov Yu. G. Yushkov 《Technical Physics Letters》2013,39(9):755-757
Results of an experimental study of the formation of rf pulses with controlled power, duration, repetition rate, and envelope parameters in a resonance compressor employing oscillation-mode transformation are presented. The pulse parameters are varied by using tuned intermodal coupling elements. A possibility of the formation of a series of subsecond and nanosecond rf pulses in the partial extraction of energy and nanosecond pulses of various durations in single complete extraction of energy from the compressor resonator is shown. 相似文献
17.
We propose to determine the delay time of coupling between self-oscillatory systems using a modification of the well-known method based on a model of the oscillation phase dynamics, which ensures its applicability in the case of nonwhite noises influencing this dynamics. For this purpose, the method of calculating a confidence interval is refined by allowance for the correlation time of the phase noise. The applicability of the proposed estimator is illustrated by the results of numerical experiments with systems of standard coupled oscillators. 相似文献
18.
The synchronization and parameter identification of six unknown parameters in a chaotic neuron model, which one parameter (about 0.006) is 3 orders of magnitude smaller than the others (about 1–5), is investigated by using Lyapunov stability theory and adaptive synchronization in detail. Two gain coefficients (δ1,?δ2) are introduced into the Lyapunov function to obtain certain optimized controllers and parameter observers. A selectable amplification factor k 0 is presented using scale conversion and it is used to improve the accuracy of parameter estimation with the smallest order. The parameter space for gain coefficient (δ) versus amplification factor k 0, and the parameter space δ1 versus δ2 at certain fixed amplification factor k 0 are calculated numerically. It is found that the selection values of optimized gain coefficients and amplification factor are critical to estimate the six unknown parameters, particularly for the smallest unknown parameters with an order 0.001. The extensive numerical results show that it is more effective to estimate the smallest unknown parameter r when the two gain coefficients δ1 and δ2 are given the same value and a higher amplification factor k 0 is used. It could be useful to estimate the unknown parameters with large deviation of order magnitude, such as a single chaotic Josephson junction coupled to a Resonant tank and other chaotic systems with potential application [Z.Y. Wang, H.Y. Liao, and S.P. Zhou, Study of the DC biased Josephson junction coupled to a Resonant tank, Acta. Phys. Sin. 50(10) (2001), pp. 1996–2000 (in Chinese)]. 相似文献
19.
M. I. Yalandin V. G. Shpak S. A. Shunailov M. R. Ul’maskulov N. S. Ginzburg I. V. Zotova A. S. Sergeev A. D. R. Phelps A. W. Cross K. Ronald S. M. Wiggins 《Technical Physics Letters》1999,25(12):927-929
Results of a simulation are presented and experimental observations of the generation of superradiance pulses in the 4 and
2mm wavelength ranges as a result of the rectilinear motion of a subpicosecond high-current electron beam through a periodic
retarding system are described. In the 4mm range the microwave pulse power reached 10–15MW with a duration of 150 ps.
Pis’ma Zh. Tekh. Fiz. 25, 1–7 (December 12, 1999) 相似文献
20.
Smotrova EI Benson TM Sewell P Ctyroky J Nosich AI 《Journal of the Optical Society of America. A, Optics, image science, and vision》2008,25(11):2884-2892
The lasing spectra and threshold values of material gain for the dipole-type supermodes of an active microdisk concentrically coupled with an external passive microring are investigated. TE polarized modes are treated accurately using the linear electromagnetic formalism of the 2-D lasing eigenvalue problem (LEP) with exact boundary and radiation conditions. The influence of the microring on the lasing frequencies and thresholds is studied numerically, demonstrating threshold reduction opportunities. This is explained through the analysis of the mode near-field patterns and the degree of their overlap with the active region, as suggested by the optical theorem applied to the LEP solutions. 相似文献