Synchronization of two resistively coupled nonautonomous and hyperchaotic oscillators

We have studied the case of hyperchaotic synchronization of two resistively coupled nonautonomous and nonlinear identical electric circuits, using the frequency and the amplitude of the input signal as the control parameters. For low values of the amplitude the two circuits can be synchronized, but for higher values of the amplitude and frequency the possibility of synchronization depends on the coupled state variable. The onset of synchronization depends on the Lyapunov dimension of the individual electric circuit.