Series-parallel Memristor Based Chaotic Oscillators And Its Application

With the rapid development of global informationization, secure communication is an extremely important basic research on national science technology and information security. Chaotic signals have non-periodic, continuous wideband, and noise-like characteristics. High quality and performance of chaotic system for secure communication have important theoretical value and highly competitive Prospects. Memristor is a nonlinear passive device with memory function and its resistance will change with the input of the excitation signal and time. Memristor can get rich variety nonlinear curve, this can increase the complexity of chaotic system and random signals. In addition, because the memristor has the properties of zero volt-ampere characteristic of curve, nano-size and low power consumption, the physical size of the chaotic nonlinear system can be greatly reduced and the energy consumption will be lowered if it is used in chaotic nonlinear system. Therefore, the chaotic oscillator based on series and parallel memristor brings the dawn of a new generation of secure communication. A new generation of chaotic oscillator with small size and low power consumption will be widely used in secure communications, spread spectrum communication and image encryption and other fields.This paper has deeply studied the single memristor. Its model is established and typical characteristics and combination of series and parallel memristor are also analyzed. The main contents of this paper include the following four parts:(1)Mathematical model of the memristor is studied. The flux-controlled and charge-controlled memristor model is analyzed, which is based on the mathematical model of HP memristor. Numerical simulations of series-parallel memristor are implemented, the SPICE circuit models are established and all these models are simulated.(2)The nonlinear characteristics of HP memristor are studied. The flux-controlled memristor is applied to Chua chaotic system. The chaotic attractor is observed and the dynamic of chaotic systems is analyzed. The discriminant method for chaotic systems and related properties of chaotic systems are analyzed. The numerical simulation of a fourth-order chaotic system based on flux-controlled memristor is carried out and its power spectrum, Lyapunov exponent and bifurcation diagrams are also analyzed.(3) A fourth-order hyperchaotic system based on two memristors in series is obtained. Not only is the dynamics analysis carried out by MATLAB, but also the implementation of this system is presented through analog SPICE circuit. The SPICE simulation results are line with the numerical analysis, which shows the generated ability of chaos in this hyperchaotic system.(4)The chaotic signal chaotic oscillator is used in image encryption. The encryption and decryption process method are analyzed. The memristor is applied to ladder signal generating circuit, and the ideal results are obtained. Finally, a chaotic oscillator circuit containing memristive devices (Memritor, Memcaptor and Meminductor) is designed and the corresponding simulation results are analyzed.Finally, conclusions are given and the future prospect of the next step of the work will be shown.