Effects of Unilateral Coupling Between Two Chaotic X-Band Gunn Oscillators

Abstract

Two X-band microwave Gunn oscillators have been separately operated with "below threshold" dc bias voltages under the influence of an injected weak RF field in their respective cavities to generate chaotic oscillations. The output of one such chaotic Gunn oscillator is injected into the other through a controllable coupling network to explore the possibility of synchronization between two oscillators. We establish through numerical simulation that (i) two oscillators with identical design parameters attain a state of complete synchronization and (ii) two oscillators with slightly different design parameters attain a state of generalized synchronization for reasonable value of coupling strengths. The occurrence of generalized synchronization has been proved through the "auxiliary" slave system approach of nonlinear analysis. Results of hardware experiments are incorporated to qualitatively support the observations made through numerical simulation.

Experimental and Numerical Studies on the Dynamics of X-Band Gunn Oscillator Based Angle Modulator–Demodulator System with Chaotic Modulating Signal

“…The effect of bias tuning is judiciously incorporated in the time variation of GO parameters. The active component of the GO, the Gunn diode, is modeled as a combination series of a nonlinear voltage dependent resistance (r(v)) and a nonlinear voltage dependent capacitance (c(v)) [Sarkar et al, 2013]. When a current i(= dq dt ) flows through the diode, v r and v c are the voltages obtained across r(v) and c(v) respectively.…”

“…When a current i(= dq dt ) flows through the diode, v r and v c are the voltages obtained across r(v) and c(v) respectively. They are written as power series functions of i and q respectively, in terms of two pairs of diode parameters (β 1 , β 3 ) and (α 1 , α 3 ) associated with the linear and the nonlinear resistance and capacitance respectively [Sarkar et al, 2013]. The distributed impedance of the cavity resonator in the microwave frequency range is modeled as a series combination of lumped circuit parameters: an inductor L, a capacitor C and a resistor R. This R takes care of the cavity loss and the external load resistor.…”

Effects of Chaotic Perturbation on a Periodic Gunn Oscillator

“…The arrangement for forcing a PGO by a CGO is designed with the help of three port circulators since a GO is a one port system. The mathematical model of this system can be derived considering the physics of operation of a forced GO by an external signal [28]. We use suffices 1 and 2 for the state variable q and system parameters a, b, c and d in the equations of CGO and PGO respectively.…”

On the mechanism of multiscroll chaos generation in coupled non-oscillatory rayleigh-duffing oscillators

“…The Rayleigh-Duffing equation arise in numerous nonlinear problems such as coupled self-sustained electromechanical devices [1], chemical processes [2], biological oscillators under periodic excitation, nonlinear system systems with multi-frequency excitation [3], and X-band microwave Gunn oscillators [4], just to cite a few. Chaotic behavior of an isolated RDO has recently attracted tremendous research efforts in recent years.…”

“…Literature studies the dynamics of a system of bilaterally coupled chaotic Gunn oscillators modelled by a pair of coupled RDOs [9]. The effects of unilateral coupling between two chaotic X-band Gunn oscillators is investigated in [4]. The output of one chaotic Gunn oscillator is injected into the other via a controllable coupling network to explore the possibility of synchronization on the effect of coupling in inducing oscillatory states between the two oscillators.…”