Millimeter-wave sensor portfolio brings precision radar to industrial and automotive applications

By Richard Quinnell, EiC

There is a growing market for sensors to monitor the position and speed of objects and not many flexible alternatives. Ultrasonic sensors cannot sense through glass or other solid barriers and optical sensors, including lidar and cameras, and they have difficulty with fog, dust, and darkness. But radar using millimeter wavelengths can overcome all of these and offer high accuracy to boot. Now millimeter-wave sensing is becoming easy enough to use that developers should consider exploring the new options available.

The rising interest in advanced driver assistance systems (ADAS) and autonomous automobile design has created a market for low-power radar using millimeter wavelengths. These radars work at short ranges, typically from 30 to 200 meters, and are used for both object detection and collision avoidance. They typically operate in the 76- to 81-GHz range with an output power up to 150 mW.

But automotive applications to detect obstacles are not the only use for such radar systems. They produce chirped signal bursts that can also be used in industrial settings to precisely measure position, angle, and velocity of a target. According to Sameer Wasson, general manager for radar and analytics processing at Texas Instruments, the range accuracy possible with millimeter-wave sensors that TI is now introducing is as fine as 100 micrometers — the width of a human hair.

Speaking with Electronic Products in a phone briefing, Wasson described the new family millimeter-wave sensor systems that TI is offering that have on-board signal processing as well as the full radio system in a single chip. Two families are available: the AWR series for automotive and the IWR series for industrial. The series include the AWR1243 radar front end intended for connection to an external signal processor, sensors with MCUs built in, and sensors with DSPs built in. All the devices work from a common software base, giving developers portability across a range of performance options.

With the entire RF system and signal processing integrated into a single chip, precision millimeter-wave angle, position, and velocity measurement fits into a 25-mm square package.

The common software base and system integration that these sensors offer bring another advantage, Wasson pointed out: simplified development. The software development kit (SDK) supporting these sensors include sample algorithms, software libraries, and a dedicated design tool that, Wasson said, lets developers get their applications up and running in 30 minutes or less. An understanding of RF is still important, he noted, but not the level of expertise that such system designs have required in the past. And TI is offering online training to help out.

If this product introduction were just a reduction of size and development effort for ADAS systems, it would be worth noting. But these single-chip systems offer such a significant increase in accuracy that they open the possibility of applications not seen before. With the onboard processing available, Wasson pointed out, a millimeter-wave system is able to detect a person’s respiration even if they are otherwise not moving. This sensitivity would allow an application such as an automobile that, as an additional safety measure, prevented locking the doors with a sleeping infant inside. In industrial applications such as level sensing, millimeter-wave sensing beats existing technologies by an order of magnitude. Other potential industrial uses might be traffic monitoring, precision obstacle avoidance for robotic systems, and the like.