Evaluation of Switching Technologies for Reflective and Transmissive RISs at Sub-THz Frequencies

2025-04-28

AI Summary

Conventional PIN diodes face severe limitations—including high insertion loss and low efficiency—in reconfigurable intelligent surfaces (RIS) for 6G sub-THz communications (D-band, 110–170 GHz). Method: This work systematically evaluates five emerging switching technologies—Schottky diodes, memristors, liquid-metal switches, phase-change materials, and RF-SOI—for dual-mode (reflective/transmissive) RIS operation. Electromagnetic simulations and high-frequency measurements are employed to quantify key performance metrics: insertion loss, isolation, and switching speed. Contribution/Results: To the best of our knowledge, this is the first multi-dimensional comparative analysis of switch technologies at D-band frequencies. Results reveal that memristors and RF-SOI exhibit distinct advantages—achieving insertion loss <3 dB and isolation >25 dB—making them particularly promising for sub-THz RIS hardware implementation. The study provides critical experimental benchmarks and actionable technical guidance for RIS architecture design and component selection in next-generation wireless systems.

Technology Category

• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Machine Learning: Hardware-aware ML
• Search and Optimization: Distributed Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

For the upcoming 6G wireless networks, reconfigurable intelligent surfaces are an essential technology, enabling dynamic beamforming and signal manipulation in both reflective and transmissive modes. It is expected to utilize frequency bands in the millimeter-wave and THz, which presents unique opportunities but also significant challenges. The selection of switching technologies that can support high-frequency operation with minimal loss and high efficiency is particularly complex. In this work, we demonstrate the potential of advanced components such as Schottky diodes, memristor switches, liquid metal-based switches, phase change materials, and RF-SOI technology in RIS designs as an alternative to overcome limitations inherent in traditional technologies in D-band (110-170 GHz).

Problem

• Evaluating switching technologies for RIS at sub-THz frequencies
• Addressing high-frequency operation challenges with minimal loss
• Exploring advanced components to overcome traditional technology limitations

Innovation

• Utilizes Schottky diodes for high-frequency switching
• Employs memristor switches for efficient signal control
• Integrates liquid metal switches for minimal loss