Single-chip, UWB radar offers a scalable sensor development platform

March 07, 2017 // By Graham Prophet
Novelda (Oslo, Norway) first disclosed its single-chip radar-based sensor technology in 2015. The company employs a low-power pulsed waveform at GHz frequencies, that comprises an ultra-wideband signal; UWB is noted for its ability to provide very accurate ranging information. The company has now released its second-generation IC, for uses in medical and health monitoring, in people- (presence-)sensing, and potentially in other sensing applications.

The XeThru Developer Platform is based on Novelda’s second-generation X4 ultra-wideband (UWB) impulse radar system-on-chip (SoC). With this technology, OEMs and system developers can implement sensors that can detect small movements, determine presence and room occupancy, and monitor respiration and other human vital signs with unprecedented accuracy and discrimination. The patient/infant monitoring application has been a key sector for Novelda, and remains a principal target. The UWB radar return can detect movements of the order of 1mm or less, through dielectric materials such as bedclothes, so can detect respiration or heartbeat at a distance.

 

Supporting various host environments, such as MATLAB, Python, C++ and C, the XeThru platform provides everything developers need to rapidly start prototyping their radar application designs. The hardware bundles an X4 SoC with an MCU board and a PCB antenna, while communications software provides an API layer that enables access to the full functionality of the SoC, and open source reference code allows the use of digital signal processing libraries to extend system performance.

 

Integrated into a single chip, the X4 UWB impulse radar SoC combines a transmitter, which can operate at centere frequencies of either 7.29 GHz or 8.748 GHz for unlicensed operation in worldwide markets, with a direct RF sampling receiver and a fully programmable system controller. The X4 SoC delivers some key performance improvements over the previous design: its frame size is now configurable for different applications and the range, for simultaneous observation, has been increased from 1m to 10m. That is, the output is a ‘frame’ that contains a signal from every reflection out to (for example) 10m. (Those unfamiliar with radar terminology might think of it as analogous to a time-domain reflectometry trace in test & measurement terms.) It is 10x faster and much more suitable for presence detection; its on-chip advanced power management functions enable low-power duty cycle control and dramatically reducing power dissipation; and its higher level