Product PQ (left plots) and linear dispersive curves (right plots) in terms of the frequency f = ω/2π and the wave number k, respectively. These graphs are obtained with the given parameters of Fig. 4 for different input parameters: (a) and (b) without the capacitor Cs in the series branch, (c) and (d) the nonlinear quadratic component of the capacitor Cs is neglected (η = 0), (e) and (f) with the effects of the nonlinear quadratic component of Cs (η ≠ 0). Panel (g) is the zoomed view of the curve in (c). |