Design and Nonlinear Dynamical Performance Analysis of Novel Improved Two-Stage Colpitts Wideband Chaotic Oscillator

Abstract

In this paper, the dynamics and nonlinear performance of novel improved two-stage Colpitts oscillators designed to operate in ultrahigh frequency range are proposed. The novel two-stage Colpitts oscillators model is described by transfering the inductance of the standard two-stage Colpitts circuit to the base of the second transistor and connect a resistor in series with the base of the two transistors in this paper. The novel two-stage Colpitts circuit not only can effectively reduce the influence of the parasitic capacitance on the resonant frequency of the circuit, but also can greatly reduce the total capacitance of the resonant network, which not only increase the fundamental frequency of the chaotic signal, but also eliminate the periodicity and make the spectrum flatter and smoother. The numerical analysis is used to solve the graph and numerical solution of the sixth order differential equation of the novel improved two-stage Colpitts circuit. The basic information of the system such as bifurcation diagram, Lyapunov exponent, phase diagram and time traces diagram, spectrum diagram and auto-correlation are obtained by numerical simulation and circuit simulation. The simulation results show that the novel improved two-stage Colpitts oscillators can work in the periodic and chaotic states, and its fundamental frequency can be increased to 5GHz., about 0.6 times the cutoff frequency of the transistor, which is 2GHz higher than that of the standard two-stage Colpitts oscillator. The spectrum of novel improved two-stage Colpitts oscillators circuit is flatter and smoother, and has no periodicity. Numerical simulations are performed to demonstrate the effectiveness and feasibility of the proposed novel two-stage Colpitts oscillators.