Memristor Based Reconfigurable Band-Stop Filter for Aerospace Applications

This article presents a reconfigurable band-stop filter (BSF) based on an open-stub design that leverages the switching properties of memristors (MR). A memristor, or memory resistor, is a two-state, programmable, non-volatile resistor known for its compact size and low power consumption. In the proposed BSF, a memristor is placed in a slit along the resonating lengths of the stub. Memristors, an emerging resistive RAM (RRAM) technology, show promising potential for reconfigurable RF applications, where they can potentially replace traditional RF switches. The tunable resistance of the memristor enables frequency tuning by adjusting the resonating length of the bandstop filter. Switching the memristor between HIGH (OFF) and LOW (ON) resistive states alters the effective resonating length. In this design, properties of Hafnium Oxide (HfO2) are used for the memristive material, though other materials with similar properties could also be used. For demonstration, a conventional open-stub BSF is used, designed to operate at 3 GHz. A slit along the resonating length accommodates the memristor which in its low-resistance state allows the full length to resonate at 3 GHz. In the high-resistance state, only the shorter length resonates, shifting the frequency upward and creating a notch at 4.345 GHz, leading to switching bandwidth of 1.289 GHz. This approach is validated through electromagnetic simulations. Incorporating the memristor as the switching element significantly reduces the power required for switching and minimizes the resonator size, paving the way for more compact filter designs. This approach also illustrates the potential for tuning RF devices without needing localized surface-mount components or complex implementation techniques. Thus, memristive reconfigurable RF filters are well-suited for aerospace needs, offering compact, tunable, and energy-efficient solutions.