Tunable coexisting states and frequency signatures of a modified Shinriki circuit

Nonlinear circuits that exhibit pronounced chaos are valued across many engineering fields. To better exploit them, this paper is concerned with tunable coexisting states in a modified Shinriki circuit, with a particular focus on frequency signatures relevant to characterization and design. First, a simple diode-based nonlinear element is constructed, which shows a polarity-selective asymmetric current–voltage ( i − v ) characteristic with an inserted DC-bias. This modification enriches the dynamical manifestations in the modified Shinriki circuit. Under a certain degree of asymmetry, distinct coexisting states are continuously tuned by adjusting the resistance in the RLC loop. Furthermore, based on the implicit mapping approach for autonomous circuits, harmonics across different orders, associated with cascaded coexisting phenomena, are decomposed. These features are systematically examined in bifurcation diagrams, amplitude spectra, and frequency spectra. Finally, the theoretical results are convincingly corroborated by the printed circuit board (PCB). Overall, this study contributes to the understanding and utilization of complex dynamics in nonlinear circuits.