Design And Simulation Of Filter Based On Memristor

The memristor is a two-terminal passive electronic element that was postulated by LeonChua, and it is used to describe the relationship between flux φ and charge q. Since the resistanceof the memristor depends on its internal state and it is characterized by nonvolatile memory, thusmemristors will be more widely used in future than other common electronic elements.The physical model of memristor that was found by HP labs is analyzed firstly in this paper,and then an improved SPICE model of memristor is proposed. A threshold voltage is introducedinto the SPICE model of memristor that based on capacitor and controlled source. When thevoltage on the memristor is less than the threshold voltage, the state of memristor changes verylittle or keeps unchanged. When the voltage on the memristor is equal or greater than thethreshold voltage, the state of memristor begins to change. In addition, a resistance controlcircuit is designed in this paper, it is used to control the resistance of memristor by changing thepolarity or duration of the output signal in the resistance control circuit.Some equivalent circuits of memory capacitor and memory inductance are analyzedsecondly in this paper, which consists of memristor, capacitors and operational amplifiers, andthey can show the performances of memcapacitative system or meminductive systemsuccessfully. And then, three kinds of filter circuits based on memristor are designed in this paper,the cut-off frequency of those filters can be adjusted by changing the resistance of memristors incircuits.From some simulation experiments in SPICE, it can be found that the characteristics of i-vand frequency in improved SPICE model proposed in this paper coincide with the ones ofphysical model that found by HP Labs. The resistance of memristor can be changed successfullyby altering output signal of the resistance control circuit, thus the cut-off frequency of filtersbased on memristors can be adjusted because of variance of memristor.