Analysis and FPGA implementation of an autonomous Josephson junction snap oscillator

An autonomous Josephson junction (JJ) snap oscillator is designed and investigated in this paper. Depending on DC bias current, the proposed snap oscillator has two or no equilibrium points. The stability analysis of the two equilibrium points shows that one of the equilibrium point is unstable and the existence of Hopf bifurcation is established for the other equilibrium point. During the numerical analysis, some interesting dynamical behaviors such as chaotic self-excited attractors, chaotic hidden attractors, antimonotonicity, chaotic bubble hidden attractors, bistable period-1-bubble and coexistence between periodic and chaotic hidden attractors are found. Finally, the Field Programmable Gate Array (FPGA) of proposed snap oscillator is implemented. The results obtained from the FPGA implementation of proposed snap oscillator are qualitatively the same to the one obtained during the numerical simulations