HfO₂-Based Reconfigurable Radio Frequency Switches for All-Memristor Multistate Attenuator

Area of Science:

• Materials Science
• Electrical Engineering
• Telecommunications

Background:

• Reconfigurable radio frequency (RF) attenuators are essential for advanced wireless systems like 5G-Advanced and 6G.
• Traditional attenuators using solid-state switches have static power consumption and high-frequency parasitic issues.

Purpose of the Study:

• To demonstrate hafnium oxide (HfO2)-based non-volatile memristors as tunable RF switches.
• To develop a switching-attenuation-integrated multistate attenuator using these memristors.

Main Methods:

• Fabrication of Au/HfO2/Ag memristor devices exhibiting stable bipolar resistive switching.
• Characterization of memristor RF performance, including ON/OFF ratio, retention, tunable ON-state resistance (R_ON), insertion loss, and isolation.
• Design and simulation of a programmable all-memristor attenuator architecture.

Main Results:

• Devices showed an ON/OFF ratio > 10^9, retention of 10^5 s, and R_ON tunable from 5.8 Ω to 197.5 Ω.
• On-wafer RF tests (10 MHz–43.5 GHz) demonstrated low insertion loss (-0.53 dB) and high isolation (-26.8 dB).
• A cascaded π-type attenuator achieved 12 attenuation levels (2–24 dB) with return loss > 10 dB and zero static power consumption.

Conclusions:

• HfO2-based memristors offer a viable solution for next-generation reconfigurable RF front-ends.
• The developed memristor attenuators are compact, low-power, and highly integrable.
• This work establishes key material-device-RF performance relationships for future RF switch designs.