From MediaTek: What is mmWave Radar for automotive?

Twenty years ago, a luxury car was defined by its CD player and cruise control. Ten years ago, in-vehicle systems featured GPS navigation and Bluetooth connectivity for hands-free calls. Today, cars can navigate, offer streaming media, can park themselves and provide voice control for many in-vehicle actions. The car is becoming not just a commuting tool, but an intelligent environment that provides ever greater safety, comfort and convenience.

In addition to its infotainment and telematics solutions, MediaTek also wants to improve the 'eyes' of the smart car system – its radar. There are three different sensing technologies the automotive sector has the option of using: ultrasonic, Lidar, and mmWave radar, with the latter two being the most recent developments.

Ultrasonic Radar

Ultrasonic radar has been used for many years, and its little sensor circles can be found dotted along the front and back sides of many vehicles on the road today. However, ultrasonic waves move at the speed of sound so they are 1,126,000,000 (1.12 x 10^-9 ) times slower than electromagnetic alternatives Lidar and mmWave radar. That's 0.0002 versus 186,000 miles per second: a colossal difference in response rate. When the car is traveling at a high speed, the information received will be delayed due to the propagation delay of the ultrasonic signal, compared to the others that provide feedback almost instantly 

Ultrasonic devices also suffer from poor directionality, requiring more devices to cover an area, and weather conditions can also greatly interfere with their effectiveness.

Lidar

Lidar uses lasers and mirrors to perform echo imaging, mapping the surrounding environment in real-time. The measurement accuracy is significantly higher than that of ultrasonic waves, but the Lidar laser can be affected by natural light or heat, resulting in occasional weak signal transmission that may affect the map of the surrounding area. Lidar units are also currently physically large and extremely expensive. While this is not a consideration for research purposes, it makes lidar difficult to become a mass-market technology that integrates easily into vehicle designs. 

mmWave Radar

Simpler than Lidar's complex mirrors and lasers, but far faster and more accurate than ultrasonic, millimeter wave radar uses highly directional, high frequency electromagnetic waves to map the surrounding environment. Operating typically at 24GHz and 77-79GHz, it can mitigate environmental factors and is not affected by heat or light. mmWave antennas are considerably smaller than ultrasonic, lower power and easily packaged into vehicle designs. They can be tuned for short, long, wide or narrow detection ranges in order to meet the needs of specific applications.

Its these distinct advantages, and our mmWave expertise, is why MediaTek committed itself to producing mmWave radar chips for automotive; where the Autus R10 is the first commercial solution available. It’s an ultra-short range mmWave radar chip that demonstrates the advantages of mmWave radar for vehicles: high integration, compact size, competitive cost, high resolution, ultra-fast response, and reliable performance.

Advantages of the Autus R10

1. The Autus R10 integrates a baseband DSP, RF, and antenna packaged into a single chip that only requires three-wires to connect it to an external ECU.
2. Applicable detection ranges from 10cm to 20m, and the minimum detection distance is less than 10cm.
3. It can be tuned to offer over 130 degrees horizontal field of view, which can significantly reduce the number of radars used. At the same time, it offers over 90-degrees vertical field of view, which is significantly greater than other sensor types and alleviates blind spots.
4. Using the higher 77-79 GHz frequency band offers down to 5cm precision, providing detailed object recognition and more precise view.
5. mmWave is billions of times more responsive than ultrasonic radar
6. Sensors can be built into the vehicle without having to drill unsightly holes in the body, unlike with ultrasonic radar.

The Autus R10 can be deployed around the vehicle to provide a total, surrounding radar system to provide real-time detection of obstacles or vehicles, providing drivers with blind spot detection (BSD), automatic parking assistance (APA), parking assistance system (PAS), and other driver safety systems. The sensors can provide a live feedback for the driver or form part of automated systems in high levels (3, 4, 5) of autonomy. The Autus R10 is already available, and in mass production.

Source: https://www.mediatek.com/blog/what-is-automotive-mmwave-radar 

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