The new Google Pixel 4 phone features the Soli 60 GHz radar chip for gesture control, the first time that radar has been used in a mobile device. While radar was developed for defense purposes, it has now made its way into our everyday life from door openers to cars to mobile devices.
Infineon wrote about the Soli technology in Microwave Journal in 2016 with “Fingertip Gesture Control Interface for "Invisible" Devices”. This article gives a nice technical overview of how it works and was developed. Google calls the sensor “Motion Sense” and it works from about a half inch from the phone face to about a foot away. It is low power and uses 60 GHz signals that don’t propagate very far and the sensor only detects general shapes and motion so does not run into privacy issues that cameras have to deal with.
According to CNET, Motion Sense can detect your presence, if you're reaching for the phone and gestures that have you decisively swipe left or right with your hand. With Motion Sense enabled, you can:
- Swipe to advance musical tracks back and forth, as with the YouTube Music app
- Swipe to dismiss an incoming call or to dismiss an alarm or timer
- Trigger the Pixel 4 screen to wake up as you reach for the device (to enable faster face unlock)
- Reduce the volume of an alarm or timer as you reach toward the phone
- Trigger the phone to turn the screen off as you walk away
In another recent release, the iPhone 11 features up to 3 cameras as its main upgrade, but the teardown shows a plethora of RF devices to utilize all of the frequency bands and wireless functions in today’s mobile devices.
The big winner in iPhone 11 seems to be Skyworks and Murata with numerous devices in the phone (and new iWatch). Skyworks has 6 modules and Murata has 4 in the iPhone 11 with Qorvo and Avago having 1 modules each. Skyworks modules include LNA/switches, PAs, FEM and GPS/LNA/filter. As these phones add 5G technology, it will be interesting to see who wins these module positions as Qualcomm hits the market with their mmWave modules to go with their existing sub 6 GHz modules which have not penetrated the market much. The Qualcomm mmWave modules seem to be leading the industry but I am sure Skyworks, Qorvo and Murata have nice designs in the works that we have not seen yet.