STOCHASTIC AND COHERENCE RESONANCES IN A MODIFIED CHUA'S CIRCUIT SYSTEM WITH MULTI-SCROLL ORBITS

Abstract

We numerically investigate the role of the number of equilibrium points (N) on characteristic features of stochastic and coherence resonances in a modified Chua's circuit model equation capable of generating multi-scroll orbits. Both types of resonances are found for 1 < N ≤ 20. Almost periodic switching between the scroll orbits is observed at resonance. The values of the signal-to-noise ratio (used to quantify stochastic resonance), the autocorrelation function and the ratio of the dominant peak and its relative width in the power spectrum of the output signal (used to characterize coherence resonance) at resonance increase with N, reaching a maximum at N = 6 and then decrease. The mean residence time of a scroll orbit at resonance decreases rapidly with N. We show that both resonances in the multi-scroll orbits can be useful for weak signal detection.