Design And Implementation Of Programmable Filter Circuit Based On Memristor

Memristor is widely used in non-volatile storage,analog artificial neural networks,analog circuits and digital circuits due to its small size,low power consumption,easy integration,and non-volatile.Memristor usually exhibit threshold voltage characteristic,that is,the resistance of the memristor changes only when the voltage across the memristor is greater than the threshold voltage,and the resistance of the memristor remains unchanged and can be used as a load resistor when the voltage is less than the threshold voltage.When the voltage is higher than the threshold voltage,the resistance can be continuously modulated by programming to achieve the dynamic adjustment of the basic circuit performance.Therefore,this new type of basic circuit element memristor can be introduced into circuit design to innovate circuit design and improve circuit performance.The filter circuit plays an important role in the fields of signal transmission,automatic control,and image processing.With the advancement of the electronics industry,more requirements have been put forward on the performance and function of filter circuits,such as small circuit size,low power consumption,high accuracy,adjustable bandwidth,and so on.Introducing memristor in the design of filter circuit,and programming resistance value,can realize programmable filter circuit with dynamically adjustable bandwidth.In this thesis,a memristor with threshold voltage characteristics and gradual change resistance is applied to a low-pass filter circuit,and the circuit design and simulation are performed in HSPICE software.The programmable circuit is designed to modulate the resistance of the memristor so that the cut-off frequency of the filter circuit is dynamically adjustable.The designed programmable circuit does not affect the normal operation of the original circuit.It has good universality and isolation,that is,it can be applied to any position in the circuit to achieve dynamic programming of the circuit.An Hf O₂ memristor with threshold characteristics and variable resistance was selected.The memristor programmable circuit and filter circuit are established for experimental verification.The verification results show that the programmable low-pass filter circuit designed has the performance of dynamically programmable cut-off frequency.In addition,the second-order and fourth-order low-pass Butterworth filter circuits based on memristor were designed and simulated,and several high-order filters based on memristor were compared and studied.The key performance indicators are the pass-band cut-off frequency of the circuit when signal attenuation of 3 d B,the stop-band cut-off frequency of the when signal attenuation of 40 d B,and the quality factor.Then compared the performance of the programmable filter circuit based on the memristor with the traditional cut-off frequency adjustable filter circuit based on the potentiometer or switched capacitor.It shows the superiority of the programmable filter circuit based on memristor,which is expected to replace the traditionally designed cut-off frequency adjustable filter circuit and improve the performance of the filter circuit.