Researchers in Japan have developed an ultra-compact, low-power radio module operating in the 150 GHz band, bringing 6G wireless connectivity closer to everyday mobile devices. Designed specifically for future 6G user equipment, the new module integrates a phased-array transceiver with key innovations that overcome the technical barriers traditionally associated with sub-terahertz communication.
The team, led by Professor Kenichi Okada from the Department of Electrical and Electronic Engineering at the School of Engineering, Institute of Science Tokyo, developed the module in collaboration with the National Institute of Information and Communications Technology (NICT) and other partners. Their findings were presented at the 2025 Symposium on VLSI Technology and Circuits in Kyoto.
With 6G aiming to deliver data rates exceeding 100 Gbps, researchers are focusing on the D-band spectrum (110–170 GHz), which provides the necessary bandwidth for ultra-high-speed and high-capacity wireless communications. However, frequencies in this range present serious challenges, including signal degradation over distance and the difficulty of designing efficient circuit components at such high frequencies.
Most current D-band transceivers have been developed for large-scale infrastructure like base stations, requiring sizable chips and bulky antennas. This has limited their use in compact devices like smartphones and IoT hardware.
The newly developed module addresses these issues through several innovative design features. One of the core breakthroughs is an injection-locked tripling phase shifter that removes the need for bulky local oscillator buffers, reducing both power consumption and chip size. This allows direct connection to the mixer while maintaining precise frequency control.
Another innovation is the bi-active sub-harmonic mixer, which operates at half the local oscillator frequency and eliminates oscillator leakage. Its dual-mode design allows both transmission and reception, further enhancing compactness without sacrificing performance.
The researchers also integrated an antenna switch directly into the amplifier’s matching network, a design choice that minimizes signal loss and allows shared use of components between transmit and receive paths. This improves efficiency and reduces the overall module size.
The resulting 8-element phased-array module measures just 8.4 mm by 20 mm and operates in the 142–164 GHz range. It achieved peak data rates of 56 Gbps, an effective radiated power of 25.7 dBm, and power consumption of only 150 mW per element in transmission mode—metrics that set a new standard for compact high-frequency devices.
These performance levels make the module well-suited for not only base stations but also compact mobile and embedded devices. This opens doors for new 6G applications such as ultra-realistic mobile VR and XR experiences in fields like healthcare, where real-time, high-resolution data is critical.
By delivering high power efficiency and bandwidth in a miniature form factor, the researchers have taken a critical step toward integrating 6G capabilities into future consumer electronics and industrial systems. The design principles demonstrated in this work are expected to influence the development of next-generation wireless technology across diverse sectors.
By Impact Lab
