Low-frequency AC-driven planar ceramic dielectric barrier discharge: Systematic effects of frequency and voltage amplitude on discharge dynamics and power coupling

This study experimentally investigates the coupled effects of excitation frequency and applied voltage amplitude on the electrical characteristics of a planar ceramic dielectric barrier discharge (DBD) operating in argon under low-frequency AC excitation. Experiments were conducted over frequency and voltage ranges of 50–500 Hz and 9–17 kV to clarify how these parameters influence discharge behavior under conditions where charge relaxation and dielectric memory effects may become significant. The results show that increasing the applied voltage amplitude primarily enhances the intensity of individual discharge events, whereas increasing excitation frequency mainly increases the microdischarge repetition rate and reduces peak current. Under simultaneous increases in frequency and voltage amplitude, the discharge evolves toward a regime characterized by a high repetition rate while partially maintaining the current amplitude, resulting in increased power deposition. Quantitative analysis further reveals a transition in pulse-number evolution from exponential growth to logistic growth at high voltage amplitudes. At 17 kV, a characteristic transition frequency of ∼302 Hz is identified, suggesting the onset of a saturation-influenced regime associated with enhanced surface-charge accumulation and memory effects. The results indicate complementary roles of applied voltage amplitude and excitation frequency in shaping discharge characteristics: voltage is more closely associated with the intensity of individual discharge events, whereas frequency has a stronger influence on discharge multiplication. These findings provide experimental guidance for optimizing stable and energy-efficient low-frequency ceramic DBD operation for plasma processing applications.