Breakthrough Low-Power Chip Powers 6G, Self-Driving Cars

Abstract

Vanadium oxide (VOx) based memristor is a promising candidate for next-generation non-volatile memory and radio-frequency (RF) switches due to its compatibility with wafer-level integration and high-frequency operation. This work demonstrates high-performance VOx memristor with gold and silver electrodes, achieving a higher cutoff frequency compared to previously reported VOx devices. The devices exhibit long retention, high endurance (≈103 cycles), and nanosecond switching speeds, enabling the fabrication of RF switches with a cutoff frequency of ≈4.5 THz, low insertion loss (< 0.46 dB), and high isolation (>20 dB) from 0.1 to 20 GHz with stable operation extended to frequency up to 67 GHz. Leveraging these switches, a reconfigurable X-band bandpass filter whose is realized center frequency is tuned from 8.2 GHz in the OFF state to 7.6 GHz in the ON state, achieving a tunable range of ≈600 MHz. This demonstration paves the way for compact and versatile RF front-ends with improved frequency agility in advanced communication systems.

A research team, affiliated with UNIST has unveiled a new semiconductor device optimized for the next-generation 6G era and autonomous driving, offering low power consumption and non-volatile operation. This innovative device can also be integrated into variable filter circuits capable of tuning the central frequency band, paving the way for more compact and energy-efficient communication equipment.

Jointly led by Professor Myungsoo Kim of the Department of Electrical Engineering and Professor Tae-Sik Yoon of the Graduate School of Semiconductor Materials and Devices Engineering at UNIST, the team announced the development of non-volatile radio-frequency (RF) switches based on vanadium oxide (VOx) for next-generation wireless communication systems.

RF switches are essential semiconductor components in modern wireless communication systems, such as autonomous systems, smartphones, VR, and AR. They control the flow of high-frequency signals within circuits by connecting or disconnecting specific pathways, enabling reliable signal routing.

The newly developed RF switch operates without standby power, functioning effectively in high-frequency bands suitable for high-speed, high-capacity communications. This is made possible by its memristor structure-a device that can retain its resistance state even when powered off, owing to its non-volatile properties. This characteristic allows the switch to maintain its set state without consuming standby power, significantly reducing energy consumption. Additionally, the memristor's resistance switching speed is on the order of a few nanoseconds, enabling rapid on/off switching and minimizing signal processing delays.

Figure 1. Schematic illustration of the overall device layout and the detailed layered configuration.

Experimental tests demonstrated that the device can handle high-frequency signals up to 67 GHz, maintaining low insertion loss (below 0.46 dB) in the ON state and high isolation (above 20 dB) in the OFF state. Lower insertion loss and higher isolation directly correspond to improved communication quality.

Simulations further indicated that the device could operate at frequencies up to 4.5 THz, representing the highest cutoff frequency reported among oxide-based RF switches to date.

The research team also developed a tunable bandpass filter utilizing this RF switch. This electronic circuit allows the center frequency to be adjusted within a range of approximately 600 MHz. Such a multi-band filter simplifies circuit design and reduces size, making it highly suitable for high-integration wireless communication devices.

Professor Kim Myungsoo stated, "The memristor-based RF switch demonstrates the potential to realize compact RF front-ends that combine frequency selectivity with energy efficiency. This development could serve as a foundational component for next-generation wireless communication systems."

The findings of this research have been published in Advanced Science on May 28 and was supported by the Ministry of Science and ICT (MSIT), the National Research Foundation of Korea (NRF), and the Korea Institute for Advancement of Technology (KIAT).

Journal Reference

Dabin Seo, Dahyeon Kim, Jiyeon Ryu, et al., "VOx-Based Non-Volatile Radio-Frequency Switches for Reconfigurable Filter," Adv. Sci., (2025).