A. V. Starodubov

First experimental observation of generalized synchronization phenomena in microwave oscillators.

In this Letter, we report for the first time on the experimental observation of the generalized synchronization regime in the microwave electronic systems, namely, in the multicavity klystron generators. A new approach devoted to the generalized synchronization detection has been developed. The experimental observations are in the excellent agreement with the results of numerical simulation. The observed phenomena gives a strong potential for new applications requiring microwave chaotic signals.

Turbulent electron beams as sources of broadband noise-like microwave oscillations

We report the results obtained from the theoretical and experimental analyses of multivelocity turbulent charged-particle beams, space-charge bunches of which are sources of broadband noise-like microwave oscillations.

Formation of turbulent electron beams for generating broadband chaotic oscillations

Oscillators of broadband chaotic oscillations, based on the use of intense turbulent electron beams, have been investigated. Different concepts of forming such beams are considered, and their structure is experimentally studied. The results of the experimental study of the oscillations generated by the broadband microwave sources developed are reported.

Wideband chaotic oscillators based on turbulent electron flows with internal electronic feedback

Wideband chaotic oscillators that operate on new physical principles, namely, using intense turbulent electron flows are studied. Various approaches to generating turbulent electron flows are considered, and the structure of the turbulent electron flow is experimentally investigated. Experimental results for oscillations generated by the suggested wideband microwave sources are reported. The generalization of analytical, numerical, and experimental data has made it possible to develop wideband chaotic oscillators based on commercial travelling-wave tubes.

Ultrabroadband generators of noiselike high-frequency and microwave oscillations with electron feedback

It is experimentally established that oscillators, such as a low-voltage vircator with electron feedback, are characterized by an ultrabroad generation band (up to four octaves and above). The minimum frequency of oscillations is on the order of 50 MHz, while the maximum frequency is about 3–3.5 GHz. The low-frequency part of the spectrum is related to the oscillations of positive ions in the interaction space.

An experimental study of the interaction between a pulsed electron beam and a large-amplitude electromagnetic wave

We experimentally investigate the interaction between an electron beam with a periodically varying diameter and a large-amplitude electromagnetic wave. The effect of different factors on the pulsed beam formation and current density in bunches is established. Compared with the electron beam deceleration circuits (low-voltage vircator systems), the generators based on pulsed turbulent beams have a broader band due to the formation of a large number of space charge bunches and an integral power efficiency that is higher by a factor of 2–2.5.

Small-size ultralow-voltage generator of chaotic microwave oscillations

The scheme of a small-size ultralow-voltage generator of broadband chaotic microwave oscillations is considered. Results of numerical modeling and experimental investigation of the device prototype operating in various regimes are summarized. Good prospects of the proposed ultralow-voltage generator (vircator) are related to the relatively low accelerating voltages (below 1000 V), rather high electron beam currents (up to 800 mA), good efficiency (up to 5%), and small dimensions of the device.

Turbulent electron beams generated by magnetron injection guns

A detailed experimental investigation of oscillators based on a magnetron injection gun is carried out. Experimental data show that such oscillators offer a considerable advantage over other similar devices; namely, they are capable of generating powerful wideband noiselike microwave oscillations. This is because magnetron injection guns generate turbulent electron beams at their exit.

Relationship between the spectra of time series of a flow system and its recurrent map

The relationship between the dynamical systems with continuous time (flows) and discrete time (maps) has been studied. It is shown how some important characteristics of a flow system can be modified during the Poincaré sectioning procedure, and which information about the flow system behavior can be obtained from the resulting map. The results of theoretical analysis are illustrated by numerical simulations for the model Rössler system and “Torus” oscillator.

Application of permutation entropy method in the analysis of chaotic, noisy, and chaotic noisy series

We have considered a permutation entropy method for analyzing chaotic, noisy, and chaotic noisy series. We have introduced the concept of permutation entropy from a survey of some features of information entropy (Shannon entropy), described the algorithm for its calculation, and indicated the advantages of this approach in the analysis of time series; the application of this method in the analysis of various model systems and experimental data has also been demonstrated.