Subthreshold Signal Enhancement in a Space-Dependent Damped Van der Pol-Duffing Oscillator via Vibrational Resonance

This paper presents a numerical study of a subthreshold signal enhancement in a Van der Pol-Duffing oscillator, via the phenomenon of vibrational resonance. The oscillator describes a particle motion in a bistable periodic potential, influenced by space-dependent damping and excited by an external bichromatic excitation. Temporal and spectral analyses approaches were employed to analyze the system response. The analyses revealed that the input low frequency signal is enhanced when the amplitude of high frequency perturbation tuned to an intermediate value. This result is also highlighted in the linear response analysis for fixed value of the damping amplitude. Moreover, the damping amplitude is found to control the system’s response. However, the best response 𝑄=7.01557is achieved for an intermediate value of the damping amplitude 𝛾=0.05.