Hysteresis loop and cross-talk of organic memristive devices

Similarly to inorganic memristors, the organic memristive devices reveal a variation of the hysteresis loop upon the frequency of the applied bias voltage. The on/off ratio of the conductivity increases from 4 to 1000 times for the variation of time delay (equilibration after the application of the voltage increment) from 5 to 60 s. Being implemented in multi-element electrical circuits memristive devices provide a cross-talk, leading to an equilibration trend of the conductivity values. This effect is mainly related to the formation of stable signal pathways.     

Memristor‐based voltage‐controlled relaxation oscillators

This paper introduces two voltage‐controlled memristor‐based reactance‐less oscillators with analytical and circuit simulations. Two different topologies which are R‐M and M‐R are discussed as a function of the reference voltage where the generalized formulas of the oscillation frequency and conditions for oscillation for each topology are derived. The effect of the reference voltage on the circuit performance is studied and validated through different examples using PSpice simulations. A memristor‐based voltage‐controlled oscillator (VCO) is introduced as an application for the proposed circuits which is nano‐size and more efficient compared to the conventional VCOs. Copyright © 2013 John Wiley & Sons, Ltd.     

Memristor‐based pseudo‐random pattern generator using relaxation oscillator

This letter presents a new pseudo‐random pattern generator using a memristor and relaxation oscillator based on an operational amplifier. The pulse width of the proposed generator is determined by the resistance storage property of the memristor, and the random pulse sequence depends on the RC time constant of the relaxation oscillator. From the simulation results, we show that the pulse width time is 7.6 μ s, and the random pulse sequence is 2048 bits. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

忆阻元件的研究进展

忆阻元件是一种联系电荷和磁链之间关系的新的无源电路元件,可以称其为第四类基本电路元件。本文首先介绍了忆阻元件的概念、基本模型及其数学表示方法,然后介绍了目前国内外的研究现状。国内研究主要集中于忆阻元件的数学模性、特性及与其它元件组成的简单电路的性能;国外的研究主要集中于忆阻元件在各方面的潜在应用以及由忆阻概念进一步推测忆容和忆感元件及其系统。     

Dynamics analysis of chaotic circuit with two memristors

Based on Chua’s chaotic oscillation circuit, a fifth-order chaotic circuit with two memristors is designed and its corresponding dimensionless mathematic model is established. By using conventional dynamical analysis methods, stability analysis of the equilibrium set of the circuit is performed, the distribution of stable and unstable regions corresponding to the memristor initial states is achieved, and the complex dynamical behaviors of the circuit depending on the circuit parameters and the memristor ini...     

Window functions and sigmoidal behaviour of memristive systems

A common approach to model memristive systems is to include empirical window functions to describe edge effects and nonlinearities in the change of the memristance. We demonstrate that under quite general conditions, each window function can be associated with a sigmoidal curve relating the normalised time‐dependent memristance to the time integral of the input. Conversely, this explicit relation allows us to derive window functions suitable for the mesoscopic modelling of memristive systems from a variety of well‐known sigmoidals. Such sigmoidal curves are defined in terms of measured variables and can thus be extracted from input and output signals of a device and then transformed to its corresponding window. We also introduce a new generalised window function that allows the flexible modelling of asymmetric edge effects in a simple manner. Copyright © 2016 John Wiley & Sons, Ltd.     

Dynamic Analysis of Fractional-Order Memristive Chaotic System

分数阶忆阻器混沌电路的动力学分析

丁大为,李书家,王年

(安徽大学 电子信息工程学院,合肥 230601)

中文说明：

为研究系统的非线性动力学,提出一个从相对应的整数阶演变而来的分数阶忆阻蔡氏电路。首先,根据李亚普诺夫间接法,对分数阶忆阻系统的稳定性进行分析,结果表明：当忆阻系统的分数阶参数达到临界值时,系统失去稳定性,并发生分岔。然后,根据不同分数阶阶数以及不同其他系统参数的分岔图表明分数阶忆阻系统发生分岔和混沌行为。此外,为证明分数阶忆阻混沌系统存在混沌行为,给出了系统的时域图、相位图和最大的李亚普诺夫指数图。最后,通过数值仿真说明和验证理论结果的正确性。

关键词：忆阻器;动力学行为;分数阶;稳定性