Feasibility study of analogue filters based on memristor

This paper reports the critical parameters in fitting the Al:HfO2 memristor and exploits the memristor symbol derived from this fitting to design filter circuits. Memristor-based filters can obtain at least two different filter ranges with the same filtering effect as conventional filters. Multistate resistance can be achieved by controlling the filamentary gap; adjusting the initial gap in the high resistance state from 1 to 0.1 nm could vary the cut-off frequency of the filters from 230 MHz to 1.54 GHz. Memristor-based band-pass filter is also simulated by cascading a low-pass filter and a high-pass filter; the results show that a cut-off frequency of 5.46 to 22.22 GHz can be tuned by adjusting the initial gap of a low resistance state from 0.4 nm down to 0.2 nm. Replacing the resistor in a conventional filter with a memristor allows the filter to have a variable range; this would solve the limitation where the conventional analogue filters have only a single filter range due to the fixed values of their constituent elements.