What's this Soli radar chip for Motion Sense in Google Pixel 4?

Google’s new Pixel 4 smartphone, announced Tuesday, comes with several new features including Motion Sense radar based on an actual Soli radar chip at the top of the phone that was developed by Google.

The radar creates an area of spatial awareness about two feet in diameter around the phone, so that it knows when a person is reaching for it or walking away from it. In that way, it can activate the screen and face unlock or turn off the always-on display, respectively.

It can also let a user skip forward or back when playing music or snooze an alarm or mute a call when the phone senses a hand waving the alarm away.

Google noted that Motion Sense is not a camera but is a type of miniature radar developed over several years in its Soli project.Google said that Soli understands movement from all angles and can detect objects through various materials. The search giant relied on a custom-built machine learning model to achieve the ability to interpret data to what it calls Quick Gestures.

Soli works by emitting electromagnetic waves in a broad beam. When it strikes a hand, some of the energy is reflected to record the amount of time it took. A change in frequency helps detect the size, shape and velocity of the object. Two modulation designs are combined in the chip: Frequency Modulated Continuous Wave radar and Direct-Sequence Spread Spectrum radar. There are also multiple beam forming antennas that enable 3D tracking and imaging. There are no moving hardware components, unlike traditional radar.

The Motion Sense feature will require owner training through a game with Pokémon. In a footnote on its website, Google notes that Motion Sense is not functional in Japan until spring 2020 “and may not be functional in other Pixel countries.” It notes that it is functional in the U.S., Canada, Singapore, Taiwan and most European countries. “Not all phone features are controlled by Motion Sense,” the note adds.

 A fuller explanation is also posted online about control, noting that Motion Sense “can tell when you’re nearby, but not who you are.” For privacy, it adds that the Motion Sense processing is on the phone and that sensor data isn’t sent to Google.

Infineon Technologies AG, based in Munich, Germany, said it developed a 60 GHz radar chip that is the "base for Google's Soli technology" used in the Pixel 4. 

One early hands-on reviewer in The Verge asked, “Is any of this really necessary? You can achieve many of these effects with an accelerometer or a camera or, you know, by touching the screen. I can’t decide if these are gimmicks or not.” 

Going back to the first Pixel phone, Google does want to try out new technologies and not necessarily to win over millions of customers. Pixels are Android phones, and they have never sold nearly as well as many other Androids from Samsung, LG and others. To paraphrase The Verge reviewer, Google has technical ambitions, more so than market dominance ambitions.

RELATED: Amazon Alexa gets intimate, in your ear, with Echo Buds

At its New York announcement, Google announced both a Pixel 4 for $799 at 5.7-inch and a Pixel 4XL for $899 at 6.3-inch. They are available for pre-order now and ship on Oct. 24. Both run on 4G cellular.

They feature a Snapdragon 855 processor, with 6 GB memory and either 64 GB or 128 GB of storage. There include main and telephoto cameras, as well as video front and rear.