Imec has unveiled the first narrowband receiver chip compliant with the upcoming IEEE 802.15.4ab standard, enabling a fourfold increase in ultrawideband (UWB) ranging distance for dense, interference-rich environments.
Standard breakthrough
Impulse-radio UWB is gaining traction in smartphones, wearables, automotive platforms, and IoT devices. However, range, scalability, and robustness limitations—especially in crowded wireless spectrum—have constrained broader adoption.
The IEEE 802.15.4ab standard, expected later this year, introduces narrowband assistance (NBA). NBA combines narrowband signaling in the 5–6 GHz range for device discovery and synchronization with UWB’s precise ranging capabilities. This hybrid approach improves efficiency, multi-user scalability, and reliability at lower signal levels over longer distances.
Technical challenge and solution
NBA imposes stringent dynamic-range and blocker-tolerance requirements. The narrowband receiver must detect weak signals with a very low noise figure while maintaining robust operation against strong Wi-Fi interferers in overlapping bands.
Imec’s design, fabricated in 22nm CMOS, features a novel second-order transimpedance amplifier (TIA) with controlled filtering. This suppresses out-of-band interferers early in the signal chain while preserving signal integrity and a low noise figure. A high dynamic-range clip detector continuously monitors operating conditions, dynamically switching to a more robust mode under strong interference and reverting to low-power mode in clean environments.
Performance metrics
The receiver consumes less than 6mW, achieving a 9dB improvement in dynamic range over prior implementations. It maintains a 3.2dB noise figure and tolerates Wi-Fi blockers around –32dBm. This sensitivity preservation under interference enables reliable narrowband-assisted UWB, supporting the fourfold ranging increase.
Imec also demonstrated the first full transceiver architecture compliant with IEEE 802.15.4ab, delivering up to a 32x improvement in ranging performance through combined receiver, transmitter, and standard innovations.
Forward-looking implications
This work enables secure, precise, low-latency relative positioning and synchronization for applications like robot-to-robot coordination and augmented reality glasses. Imec is exploring extending the NBA architecture to other low-power wireless systems, including future Bluetooth evolutions. Industry partnerships are underway to accelerate IP transfer and commercialization.
Imec’s validation of the NBA mechanism marks a critical inflection point for UWB, transforming it from a niche technology into a scalable, robust platform for next-generation wireless ecosystems.
