Abstract: A novel three- dimensional autonomous chaotic system is constructed,which is the general structure of the Lorenz system,Chen system and Lü system. The dynamic properties of the new system are analyzed via Lyapunov dimension,Lyapunov exponent spectrum,bifurcation diagrams when system parameters vary. The Lyapunov exponent spectrum is locked when the parameters of the quadratic cross- product terms vary. The bifurcation diagrams and state variable evolutions of the locked chaotic systems show that the amplitude evolvement and the phase of the chaos signals can be modulated. Finally,the circuit of the new chaotic system is designed and realized by Multisim software,and results show a good agreement between theory analysis and circuit simulations.

Key words: chaotic system, double invariable Lyapunov exponent spectrum, nonlinear modulation, phase reversal