MADISON, Wis. — Many carmakers, in order to increase the real-world situational awareness of their highly automated vehicles, have already accepted the necessity of literally surrounding every chassis with different types of sensors. What’s not given, however, is the quality of these sensors. How good, for example, are vision, lidar and radar sensors today, and how much better do they have to get?
Metawave Corp., spun out of PARC, a Xerox company based in Palo Alto, Calif., thinks it can alter what the automotive industry perceives as the “limitations” of conventional radars. Today, automotive radars can’t see faraway objects and can’t discriminate what they see. They operate at processing speeds that aren’t fast enough for the highway.
In short, today’s automotive radar can’t see objects that a camera or lidar can see. Its only saving grace is that it operates in all-weather conditions.
Leveraging an exclusive license it received from PARC to commercialize metamaterials radar and antennas, Metawave, founded in Janauary, is touting its “full radar package.” It plans to show off a prototype at the Consumer Electronics Show in January 2018.
Metamaterials are small software-controlled engineered structures, laid out on a printed circuit board. They are said to be able to steer electromagnetic beams in ways that were previously only possible with the much larger, powerful and more expensive systems typically confined to military use.
Metawave, however, isn’t blaming radar chips — designed by such suppliers as NXP, Infineon or Texas Instruments — for the problems of today’s automotive sensors. In fact, Metawave’s full radar package is radar chip agnostic. Rather, the startup blames the beam-forming technology in radar sensors, including the antenna, for causing problems in resolution and speed.
Back to analog
Maha Achour, Matawave’s CEO, believes it’s time the industry gets “the radar platform back to analog.” Stressing that “we still exist in the analog world, and so does the car,” she said Metawave intends “to build an affordable, high performing analog radar platform without the complexity and cost that we would see in military-grade operations.”
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Metawave’s analog radar technology is based on an electronically steerable antenna. It uses a single antenna with two ports, one connected to the Tx or Rx chain and the other one to the MCU. The MCU defines and controls antenna beamwidth and direction by using lookup table, allowing Metawave’s analog radar to attain micro-second speed scanning. (Source: Metawave)
By using a single antenna, Achour claims Metawave has designed an analog radar that can steer and shape a beam in the horizontal and vertical directions, and adjust the beam from a wider field of view to a very narrow cone — down to one degree. "And we can do it very fast -- not in milliseconds, but in micro-seconds,” Achour said.
But how does Metawave’s analog radar compare with the digital radars now conventional in vehicles?
Radars based on digital beam forming (DBF) technology require antenna arrays to focus the electromagnetic signal emitted by a transmitter in a specific direction and steer it in other directions. The receivers then acquire return signals from objects and process them digitally to form an image of the scene.
To enable this process, digital radar must “inject different phase delays at each antenna to make the beams add constrictively in one direction and destructively along others,” Achour explained.
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