Meaning
Modification of the emitted electromagnetic radiation profile occurs when physical structures block or refract signal paths. This antenna pattern distortion degrades the gain, increases side lobe levels, and alters the main beam direction of a radar module. The boundary of this effect is defined by the physical spacing between the antenna array and the surrounding vehicle bumper or radome.
Radiation Alteration
Millimeter-wave signals require a clear, unobstructed path to propagate without phase shifts or attenuation. When antenna pattern distortion occurs, the directional sensitivity of the receiver changes unpredictably. This degradation reduces the signal-to-noise ratio and limits the detection range for small targets.
Radome Interaction
Protective housings placed over radar modules must be matched to the operating wavelength. A mismatch in radome thickness or material composition creates internal reflections that interfere with the outgoing wavefront. These reflections redirect energy away from the primary transmission axis into unintended directions.
High-precision automated test benches map the resulting signal degradation by rotating the housing relative to the source and plotting the changes in power density.
Angular Resolution
Driver assistance systems rely on precise angle-of-arrival calculations to separate closely spaced targets. Uncontrolled changes in the antenna pattern introduce phase errors that translate into incorrect target bearings. System validation at the assembly level requires measuring the radiating pattern to confirm it remains within acceptable regulatory and functional limits.
