The achievement is being seen as an important step in the development of radar-based sensors for a myriad of smart intuitive applications, such as building security, remote health monitoring of car drivers, breathing and heart rate of patients, and gesture recognition for man-machine interaction
Radars are extremely promising as sensors for contactless, non-intrusive interaction in internet-of-things applications such as people detection & classification, vital signs monitoring and gesture interfacing.
However, a wide adoption will only be possible if radars achieve a higher resolution, become much smaller, more power-efficient to run, and cheaper to produce and to buy. This is what imec’s research on 140GHz radar technology targets.
This low-power 140GHz radar solution comprises an imec proprietary two antenna SISO (Single Input Single Output) radar transceiver chip and a frequency modulated continuous wave phase-locked loop (FMCW PLL), off-the shelf ADCs and FPGA and a Matlab chain. The transceiver features on-chip antennas achieving a gain close to 3dBi. The radar link budgets are supported thanks to the transmitter Effective Isotropic Radiated Power (EIRP) that exceeds 9dBm and a receiver noise figure below 6.4dB. Total power consumption for the transmitter and receiver remains below 500mW, which can be further reduced by duty cycling.
The FMCW PLL enables fast slopes over a 10GHz bandwidth
around 140GHz with a slope linearity error below 0.5% and has a power consumption below 50mW. The FPGA contains real-time implementation of basic radar processing functions such as FFTs (Fast Fourier Transforms) and filters, and is complemented by a Matlab chain for detections, CFAR (Constant False Alarm Rate), direction-of-arrival estimation and other advanced radar processing.
“With our prototype radar, we have demonstrated all critical specs for
radar technology in 28nm standard CMOS technology,” said Wim Van Thillo, IoT program director at imec. “We are well advanced in incorporating multiple antenna paths in our most recent generation solution, which will enable a fine angular resolution of 1.5cm in a complete MIMO radar form factor of only a few square centimetres. We expect this prototype in the lab by the end of 2018, at which point our partners can start building their application demonstrators.
"First applications are expected to be person detection and classification for smart buildings, remote car driver vital signs monitoring (as cars evolve towards self-driving vehicles), and gesture recognition for intuitive man-machine interactions. Plenty more innovations will be enabled by this technology, once app developers start working with it.”