VLSI Symposium: Imec's low

Belgian lab Imec is claiming record ranging precision and power consumption for a novel 6 – 9GHz IEEE 802.15.4z UWB (ultra-wide-band) impulse-radio transceiver: 1.4mm ranging, and 8.7mW Tx plus 21mW Rx consumption in continuous mode.

"It paves the way for a variety of automotive applications," according to Imec. "One use-case includes the creation of radar-on-chip systems for in-cabin child presence detection, and driver monitoring."

Fabricated in 28nm CMOS technology and occupying 1.33mm2, the chip has three receivers and one transmitter. Its "low power consumption results from a optimised interference-resilient Rx architecture, coupled with a digital polar transmitter architecture", said Imec.

Also for power reduction, the PLL is an all-digital two-stage design and, to improve ranging performance without breaking the spectrum regulations, and analogue FIR (finite impulse response) Tx pre-emphasis pulse shaping has been used.

This is not the labs first UWB creation. It revealed a sub-5mW IEEE 802.15.4z UWB transmitter IC in 2021 and a 1.66Gbit/s UWB radio last year.

"Industry requires high-performance, low-power UWB transceivers that can support a multitude of use cases, so that is what we are presenting today." said Imec wireless sensing director Christian Bachmann. "We believe this chip could ultimately support a generation of UWB use-cases combining ranging, communications and radar functionality."

Smart industry, smart home and IoT applications are also foreseen – for example, centimetre-accurate asset location in warehouses, hospitals and factories, and indoor navigation in large voids such as airports and shopping malls – where narrow-band technologies such as Bluetooth do not range so well, said Imec, adding: "On the downside, UWB impulse radio uses more complex and expensive circuits and typically exhibits higher power dissipation."

It will present ‘An 8.7 mW/Tx, 21 mW/Rx 6-to-9GHz IEEE 802.15.4a/4z compliant IR-UWB transceiver with pulse pre-emphasis achieving 14mm ranging precision’ on the Tuesday of the Symposium on VLSI Technology and Circuits in Kyoto (11 – 16 June).