We describe an extremely simple second order analogue electrical circuit for simulating the two-well Duffing-Holmes mathematical oscillator. Numerical results and simulations are illustrated with snapshots of chaotic waveforms, phase portraits (the Lissajous figures) stroboscopic maps Poincar´e sections).

Experimental results demonstrating chaotic performance of the Colpitts oscillator in very high frequency (30–300 MHz) and ultra-high (300–1000 ranges are reported. Period-doubling route to chaos is revealed, confirming dynamical nature oscillations. Broadband continuous power spectra presented.

A novel version of the chaotic Colpitts oscillator is proposed. It contains two bipolar junction transistors coupled in series. The resonance loop consists an inductor and three capacitors. two-stage oscillator, compared with classical circuit, enables fundamental frequency oscillations to be increased by a factor three. PSpice simulations performed 9 GHz threshold demonstrate that highest frequencies behaviour are 1 3 for respectively.

A novel version of the Colpitts oscillator is presented generating chaotic oscillations at gigahertz frequencies. In contrast to standard inductor moved from collector circuit transistor base circuit. PSpice simulations demonstrate chaos fundamental frequencies 0.5, 1 and 2 GHz employing transistors with a threshold frequency 9 GHz.

A chaotic oscillator, including a nonlinear unit, an amplifier, RC filter and delay line, is described. Depending on the gain circuit exhibits mono- or two-scroll oscillations. The oscillations, in comparison with mono-scroll are characterised by three times higher fundamental frequency.

We demonstrate that a dynamical system can be switched from stable steady state to previously unknown unstable (saddle) using proportional feedback coupling an auxiliary system. The simplest one-dimensional nonlinear model is treated analytically, the more complicated two-dimensional pendulum considered numerically, while damped Duffing-Holmes oscillator investigated and experimentally. Experiments have been performed simplified version of electronic Young-Silva circuit imitating behavior...

We suggest employing the first-order stable RC filters, based on a single capacitor, for control of unstable fixed points in an array oscillators. A capacitor is sufficient to stabilize entire array, if oscillators are coupled strongly enough. An composed 24 30 mean-field FitzHugh–Nagumo (FHN) type asymmetric oscillators, considered as case study. The investigation has been performed using analytical, numerical, and experimental methods. analytical study approach, characteristic equation...

Monte Carlo computer simulations of electron impact ionization in InSb crystal are carried out for both instantly switched on dc and high-frequency electric fields. It is established that the rate generation electron–hole pairs decreases with increase field frequency, due to inertia heating by field. For fields oscillating at frequencies much higher than reciprocal momentum relaxation time, threshold found be a linear function frequency. Good agreement between calculations available...

Abstract Electronic properties of InSb and InAs are sensitive to electric field due their narrow forbidden energy gaps big difference in effective masses electrons different conduction band valleys. Here we report impact ionization processes redistribution between the Γ, L X valleys induced by a single ultrashort terahertz (THz) pulse at 80 K temperature. Monte Carlo simulation revealed that electron motion this case has near ballistic character. The threshold increases as THz gets shorter,...

A novel version of chaotic Colpitts oscillator is described. Instead a linear loss resistor, it includes an extra inductor and diode in the collector circuit transistor. The modified comparison with common may generate oscillations at fundamental frequency f* noticeably closer to threshold f T employed bipolar junction transistor, up ≈ 0.6f .

An array of globally all-to-all coupled FitzHugh-Nagumo--type oscillators is considered. We suggest an adaptive first-order stable filter control feedback technique to stabilize the steady states oscillators. The overall system includes separate networks coupling and control. Therefore, controller does not depend on intrinsic parameters between have investigated stabilization in nonidentical analytically, numerically, experimentally.

Damping of spikes in an array coupled oscillators by injection sinusoidal current is studied both electronically and numerically. The effect investigated using consisting thirty mean-field FitzHugh–Nagumo-type oscillators. results are considered as a possible mechanism the deep brain stimulation used to avoid symptoms Parkinson's disease.

A synergetic control technique for stabilizing a priori unknown saddle steady states of dynamical systems is described. The method involves an unstable filter combined with derivative feedback. cut-off frequency the not limited by damping system, and therefore can be set relatively high. This essentially increases rate convergence to state. robust influence external forces, which change coordinates state in phase space.

An adaptive feedback method for tracking and stabilizing unknown and/or slowly varying saddle-type steady states of conservative weakly damped dissipative dynamical systems is proposed. We demonstrate that a saddle point can be stabilized with neither unstable nor stable filter technique. The proposed controller involves both filters working in parallel. As specific example, the Lagrange L2 Sun-Earth system discussed second-order model considered. Analog simulations have been performed using...

A control method for desynchronizing an array of N mean-field coupled modified FitzHugh–Nagumo oscillators is described. The technique based on filtering the mean field sampled at coupling node. first order branched RC filter composed resistors and a single capacitor. can be applied to arrays in wide range strength (in general, unknown strength) between individual oscillators. Both numerical simulations hardware experiments with electrical circuit imitating dynamics model have been performed.

A feedback method for stabilizing the steady states in an array of coupled nonlinear oscillators is described. The employs two complementary techniques: pinning control accomplished via a single accidentally accessed (or randomly chosen) oscillator and repulsive mean field. Analytical, numerical, experimental results are presented chain diffusively FitzHugh–Nagumo (FHN) type with exponential activation function. experiment has been performed using analog electrical circuit, imitating...