World’s First IEEE 802.15.4ab Receiver Debuts from imec
A new IEEE 802.15.4ab-compliant 22nm CMOS implementation uses narrowband assistance to improve indoor localization performance and mitigate heavy Wi-Fi interference.
Ultra-wideband technology has become a staple for precise spatial awareness in mobile devices and automotive entry systems. However, traditional implementations face significant limitations in range and reliability when deployed in crowded wireless environments. To address these challenges, the upcoming IEEE 802.15.4ab standard introduces a concept known as Narrowband Assistance. By offloading synchronization and device discovery to a separate narrowband control link, the primary ultra-wideband radio can focus entirely on localized ranging tasks.
Imec has developed the industry’s first receiver chip designed specifically to validate this new standard. Fabricated in a 22nm complementary metal-oxide-semiconductor process, this radio frequency receiver expands the operational range of ultra-wideband systems by up to four times. The main engineering hurdle for such a device is maintaining an exceptionally low noise figure to catch weak, distant signals while simultaneously resisting strong out-of-band interference from nearby Wi-Fi networks.
Overcoming the Blocker Challenge with Advanced Filtering
The architecture achieves this balance through a custom analog front-end. It features a specialized second-order transimpedance amplifier that filters out heavy out-of-band blockers early in the signal chain. This prevents the receiver from saturating when operating near powerful interference sources.
Additionally, the chip incorporates an automated clip detector. When the radio detects a high-interference environment, it dynamically switches to a high-dynamic-range mode, enabling additional filtering and gain adjustments. In cleaner RF environments, it reverts to a low-power state to preserve battery life.
Interference-rich industrial floors have long constrained UWB’s range and reliability, the conditions the new IEEE 802.15.4ab standard was designed to overcome. Image used courtesy of Adobe Stock
Performance Benchmarks and Future Integration
In terms of measured performance, the receiver consumes less than 6 milliwatts of power while maintaining a 3.2-decibel noise figure. It offers a 9-decibel improvement in dynamic range compared to existing alternatives and can tolerate Wi-Fi interference up to -32 dBm. Imec also demonstrated a full transceiver pairing this receiver with a compatible transmitter, resulting in a 32-times overall improvement in ranging efficiency.
This development opens up compelling possibilities for next-generation wireless systems. The hardware is exceptionally well-suited for industrial robotics requiring precise coordination, secure hands-free access control, and augmented reality devices. Seeing this architecture transition into commercial Internet of Things devices and potentially influencing future Bluetooth standards will be a fascinating progression to watch as cross-protocol wireless coordination becomes the norm.
