The inside story of the world’s first millimeter-wave radar system on chip, part 1

Sep 29, 2020
 

When TI innovators created the world’s first millimeter-wave radar system on chip, we enabled our customers to integrate radar sensing technology into an array of applications that help improve safety on the road and in factories, and could even help firefighters see through smoke to save lives.

Imagine a low-cost radar sensor that could be affixed to a firefighter’s helmet in order to detect an unconscious or incapacitated person through walls and smoke.

TI engineers have created a millimeter-wave (mmWave) radar sensor that in the future could “see” through drywall and other obstructions and provide an audible alert to users based on what is perceived by 3D imaging.

“mmWave works extremely well at penetrating smoke and seeing through drywall,” said Brian, an innovator on the core team that created TI mmWave technology. “The challenge for this application is that you are trying to detect breathing motions of an incapacitated person while the emergency responder himself is moving. As with many of its applications, mmWave technology will only continue to evolve and improve to overcome challenges and be used in more potentially life-saving applications.”

Firefighter looking through wall using mmWave technology

Similar technology is being used by our customers today behind automobile bumpers to see an obstruction on the road to alert the driver. TI mmWave technology is also being designed in to an application that will sense a child left unattended in a car to alert the parent, and is being considered for applications including detecting when an elderly person falls to alert a caregiver and enabling robots to navigate complex factory environments.

When a small research and development team began working on TI mmWave technology in 2009, they didn’t realize the number of applications the technology would one day enable. The original intent of the technology was to provide a radar sensor that was affordable enough to be incorporated into low-cost vehicles. Prior to this technology, radar sensing was only available in very expensive cars.

Radar and how it works

The concept of radio detection and ranging, which later became an acronym, RADAR, was invented during World War II to help detect enemy invasion and has been widely used ever since. In addition to its pioneering military uses, radar technology enables air and ground traffic control, weather forecasting and medical monitoring, along with advanced safety features in cars.

Many radar systems of yesterday were large and expensive, with military applications reaching millions of dollars and hundreds of feet in size. They also operated at low frequencies, which produce much-less-precise imaging.

TI mmWave radar sensors operate at 60 GHz or 77 GHz for much higher precision. They are also small and compact, about the size of a quarter, and produce images so detailed that you can see outlines of objects and classify them.

mmWave radar works by transmitting a waveform, which goes out, bounces off an object and comes back. The technology is robust and can mitigate interferences, even in degraded environmental conditions.

“We are able to measure the time between when we sent out the waveform and the time we received it back and also the direction that it’s coming, and from there, we are able to ‘see’ what is out there in space,” Brian says.

In a system to detect an unattended child left in an automobile, the waveform would transmit from the ceiling of the vehicle into the cabin of the parked car. If an infant or toddler were in the car, the waveform would bounce off their chest, and the technology would detect their breathing and communicate to the central processor to alert the driver, honk the horn or crack the windows to allow air to come in.

The challenge of CMOS

When the project kicked off in 2009, the team accepted the steep challenge of designing in CMOS (complementary metal–oxide–semiconductor) technology because they knew that this foundational technology was what would make TI mmWave radar affordable to the masses. It was the one thing that would allow the team to bring radar detection capabilities, which were once very costly, to a technology that is affordable enough to easily be incorporated into a $20,000 car.

To become familiar with millimeter wave technology, the team worked from 2009 to 2012 to develop a 160-GHz radar for very short distance communications applications.

At the time, no one in the world had built such a system using CMOS technology.

“That was the biggest disruptor – to enable building automotive millimeter wave devices in CMOS,” Brian says. “That by itself took a tremendous amount of innovation across the devices, the circuits and the test solutions.”

And the competitive landscape for radar devices was stiff, Brian recalls.

“Our competitors had the state-of-the-art solutions in automotive radar,” he remembers. “They were built in silicon germanium bipolar technologies, which are more expensive and can be difficult to integrate. At TI, we took a different path and focused exclusively on using advanced CMOS technologies because they have better cost structure, lower power and potentially higher performance.”

The team worked three years to complete its first project. By early 2012, they had proven that they could build mmWave systems in CMOS, and they were trying to figure out the right commercial opportunity to take the technology to market. 

“We looked at whether we could make an impact in automotive radar for advanced driver-assistance systems and decided we would be able to disrupt that market, to bring in CMOS and really enable higher performance, lower cost and lower power, simultaneously,” Brian says.

Living our passion by making TI mmWave more affordable

At TI, our passion is to create a better world by making electronics more affordable through semiconductors. Innovations like mmWave demonstrate our passion in action. Like many TI engineers over the decades who helped lay the foundation for today’s breakthroughs, the innovators who developed this technology did so with a fierce desire to beat the competition and a singular focus on the goal to bring affordable radar sensing technology to mid- and low-end automobiles.

Next week, join us to learn more about the TI mmWave innovation journey and the people who made it all possible, including core innovators Baher, Vijay, Brian and Srinath.