Vehicle Radar Sensors

Radar sensors are a core ADAS hardware technology, complementing cameras and LiDAR. They use radio waves to measure object distance, speed, and direction, functioning reliably in poor visibility conditions such as fog, rain, or darkness. Most EVs deploy multiple radar units for adaptive cruise, collision avoidance, and blind-spot monitoring.

What Radar Sensors Do

• Adaptive Cruise Control – Maintain safe following distance by tracking vehicle speed and position
• Collision Avoidance – Detect obstacles and trigger emergency braking
• Blind-Spot Monitoring – Monitor side zones to support lane-change safety
• Cross-Traffic Alerts – Identify approaching vehicles when reversing
• All-Weather Sensing – Operate effectively in low light or adverse weather

Why They Matter

Radar adds depth perception and motion tracking that cameras alone cannot provide. While LiDAR offers higher resolution, radar remains cheaper, more robust, and less power-hungry, making it a mainstay of cost-sensitive ADAS deployments.

There are several types of radar sensors used in vehicles, including 2D, 3D, and 4D sensors. Here is a brief overview of each type:

2D Radar Sensors: 2D radar sensors emit radio waves in a single direction and then measure the time it takes for the waves to bounce back from an object. These sensors provide information about the distance to the object but do not provide any information about its height or shape. 2D radar sensors are often used in blind spot detection systems and rear parking assist systems.

3D Radar Sensors: 3D radar sensors emit radio waves in multiple directions and can provide information about the distance, height, and shape of an object. These sensors are often used in collision avoidance systems and adaptive cruise control systems, as they can help the vehicle's onboard computer make more informed decisions about how to maneuver the vehicle.

4D Radar Sensors: 4D radar sensors are a type of 3D radar sensor that also provides information about the object's speed. This allows the vehicle's onboard computer to make more accurate predictions about the object's future position, allowing it to make more precise maneuvers to avoid a collision. 4D radar sensors are often used in advanced driver assistance systems (ADAS), such as lane departure warning systems and automatic emergency braking systems. 4D radar sensors provide the most comprehensive data and allowing for more advanced driver assistance systems.

Vendor Landscape

Tier-1 suppliers such as Bosch, Continental, Valeo, Aptiv, and Denso dominate radar module production. Startups and niche players are introducing 4D imaging radar, which provides finer resolution for higher-level autonomy. Automakers are increasingly pairing radar with AI inference to achieve more advanced perception in mass-market EVs.