忆容器多谐振荡器及其实验

Memcapacitor-based multivibrator and its experiments

忆容器是一种具有记忆性的非线性电容,为研究忆容器的电路特性,提出了一种压控型忆容器的二次曲线模型,利用电流反馈型运放等器件构建了能够动态模拟忆容器q-v特性的仿真器.通过仿真和实验观测到忆容器的滞回曲线,以及随外加激励频率增加而收缩的特性.分析了周期性激励信号的参数对忆容值取值范围的影响,并对忆容器的非易失性和平衡点的稳定性进行了研究.基于该忆容仿真器设计了一种多谐振荡器,分析了振荡器的工作原理,对振荡器的输出电压、忆容器的端电压、忆容器的磁通和电荷,以及忆容器的滞回曲线进行了测试.通过实验中观测到的各种振荡波形,分析了振荡器的频率、占空比以及忆容器的非线性特性随电路参数变化的规律.

Memcapacitor is a kind of non-linear capacitor with memory capability.In order to study the electrical characteristics of memcapacitor and its application circuit,a quadratic model of voltage-controlled memcapacitor is proposed,and an emulator which can dynamically simulate the q-v characteristics of the memcapacitor is designed by using a current feedback operational amplifier,multiplier and other devices.The emulator does not need to be converted by any memristor or meminductor.It can work in floating or grounding state.The constitutive relation of the memcapacitor emulator is deduced,and the circuit parameters of the emulator are designed.Based on the simulations and experimental results,the pinched hysteresis loop and its dependence on frequency are verified.In addition,the range of the memcapacitance under periodic signal excitation is discussed and the influence of periodic excitation signal on the range of memcapacitance is analyzed.Through observing the dynamic route map(DRM)of the memcapacitor,its nonvolatility and the stability of the equilibrium point are also studied.The simulation results show that the memcapacitor can exhibit infinite stable equilibrium points and can be stabilized at any equilibrium state.With respect to pulse excitation signal,the effects of pulse width and amplitude on the switching on or off of the state for the memcapacitor is analyzed,and the corresponding switching method and rule are proposed.This characteristic of memcapacitor makes it have potential applications in non-volatile memory,neural network and other fields.Based on the proposed memcapacitor model,a multivibrator circuit is designed.Then,the working principle of the oscillator is analyzed,and the equation of oscillator is derived.The output voltage of the oscillator,the terminal voltage of the memcapacitor,the flux and the charge of the memcapacitor,and the pinched hysteretic curve of the memcapacitor during oscillation are tested experimentally.Besides,various oscillation waveforms whose frequency and duty cycle are different are observed and further analyzed.The circuit structure of the memcapacitor multivibrator designed in this paper is very simple.It can generate stable rectangular wave signals with controllable frequency and duty cycle,and it can be used in testing signal or driving the device.