4D Millimetre-Wave Imaging Radar

4D millimetre-wave imaging radar is an advanced radar sensor that builds upon conventional 3D millimetre-wave radar (range, velocity, azimuth angle) by adding elevation angle/height data, thereby delivering comprehensive four-dimensional perception across range, velocity, azimuth, and height. It also outputs high-density point cloud data to outline target contours, earning it the moniker of an "imaging" radar.

💡 Operating Principle: The Perception Leap from "Planar" to "3D"

A major shortcoming of conventional 3D radar is its lack of vertical resolution, which often causes overhead fixtures like road signs and flyovers to be misidentified as road hazards, triggering "phantom braking". 4D imaging radar resolves this issue via the following core technologies:

• Enhanced vertical resolution: The key innovation lies in arranging antennas along the vertical axis within the radar array, giving it the capability to measure elevation angles. This allows the system to distinguish whether an obstacle is on the road surface or suspended overhead.

• MIMO virtual aperture technology: To significantly enhance resolution without multiplying physical antennas, 4D radar widely utilises Multiple-Input Multiple-Output (MIMO) technology. By coordinating multiple transmitting and receiving antennas through signal coding, it "virtualises" a much denser antenna array, effectively expanding the radar aperture to dramatically sharpen angular resolution from 5°–10° on conventional units to 1°–2°, with premium solutions achieving up to 0.5°.

• Architectural evolution: Beyond the traditional "edge computing" setup (where the radar unit processes data locally), a "satellite" or "distributed" architecture has also emerged. Under this setup, the radar merely captures raw signals and relays them to a central domain controller for unified processing, lowering individual hardware costs while consolidating vehicle compute power.

📊 Core Advantages and Market Positioning

4D imaging radar maintains stable, dependable detection in adverse conditions such as heavy rain, fog, and night driving where cameras and LiDAR performance degrades, making it pivotal for true all-weather sensing. In smart driving systems, it serves two primary functions:

1. Safety redundancy: It acts as a critical backup to cameras and LiDAR, providing a failsafe in edge cases. For instance, its electromagnetic waves can bounce beneath the vehicle ahead to detect occluded traffic further in front—a feat other sensors struggle to achieve.

2. Cost-effective primary solution: Costing roughly one-fifth of a low-channel LiDAR unit, it has become the go-to choice for value-focused smart driving systems, delivering solid perception capabilities without relying on expensive LiDAR hardware.

🚀 Industry Status: From Niche Tech to Mainstream Standard

4D imaging radar is entering a phase of rapid market adoption. In 2025, factory-fitted OEM volume in the Chinese market surpassed 15.17 million units, marking a year-on-year surge of 862%. 2026 is widely regarded as its breakout year for large-scale vehicle deployment.

• Rapid tech iteration: Taking the 8T8R architecture FVR60 4D radar jointly developed by Freetech and Infineon as an example, its maximum detection range reaches 350 metres, with azimuth and elevation angular resolutions rated at 0.9° and 1.2°, respectively.

• Trickling down to mass-market models: The technology has quickly expanded from flagship models like the Maextro S800 and NIO ET9 down to mainstream RM100,000–RM200,000 segment offerings from Xiaomi, Onvo, and BYD (God's Eye C platform).