Behind-License-Plate Radar Array for Sub-Degree Angular Resolution

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Solution Overview

Problem

Existing front radar sensors in automotive applications face challenges in achieving high angular resolution due to integration difficulties and signal distortions caused by varying material properties of vehicle components, which affect radar detection performance and accuracy.

Innovation Solution

A radar system with a two-dimensional antenna array arrangement on a large area, typically behind the vehicle's license plate, utilizing a MIMO configuration with antennas placed on the edges to minimize interference from license plate materials and characters, allowing for improved resolution and integration without affecting aesthetic or aerodynamic properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar sensors with larger physical apertures are used to achieve higher angular resolution, then measurement precision is improved, but device complexity and integration difficulty increase

Engineering Contradiction:
Improveangular resolutionVSAvoidintegration difficulty
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from conventional one-dimensional linear antenna arrays to two-dimensional planar antenna arrays. This dimensional change enables the radar system to achieve higher angular resolution (sub-degree level) without proportionally increasing the physical aperture size, thereby reducing integration difficulty while maintaining measurement precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent divides the large aperture into multiple smaller antenna elements arranged in a two-dimensional grid pattern. This segmentation allows the system to achieve high angular resolution through spatial distribution of multiple small elements rather than requiring a single large aperture, simplifying integration into vehicle bumpers and fascias.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If radar sensors are integrated behind the front bumper or fascia to maintain aesthetic and aerodynamic properties, then ease of operation is improved, but signal quality deteriorates due to material interference

Engineering Contradiction:
Improveaesthetic integrationVSAvoidsignal quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a specialized antenna substrate as an intermediary layer between the radar electronics and the vehicle's plastic bumper/fascia. This substrate is designed with specific electromagnetic properties to minimize signal attenuation and distortion caused by the plastic materials, thereby maintaining signal quality while allowing aesthetic integration behind the bumper.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes the electromagnetic parameters (permittivity, permeability, thickness) of the antenna substrate to compensate for the attenuating and distorting effects of the plastic bumper materials. By adjusting these parameters, the system maintains reliable signal transmission while integrated behind the aesthetic coverings.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If antennas are arranged on a large two-dimensional area to achieve sub-degree resolution, then measurement precision is improved, but the area required for installation increases

Engineering Contradiction:
Improveangular resolutionVSAvoidantenna placement area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent employs two-dimensional antenna arrays that utilize both horizontal and vertical spatial dimensions efficiently. This allows the system to achieve sub-degree angular resolution with a compact footprint by distributing antennas across a planar surface rather than requiring a large linear aperture, thus reducing the overall installation area required.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves sub-degree level resolution and enhanced radar performance by optimizing antenna placement and material selection, reducing signal distortions, and enabling integration into various vehicle models without additional modifications.

Implementation Method 1

Radar sensors are used in automotive applications (e.g. in motor vehicles such as cars) to provide safety and comfort functions

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

The varying material properties of the elements covering the radar sensors can massively influence the radar signal quality

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 3

Since the radar antennas are arranged on a relatively large two-dimensional area, the radar system has an improved, sub degree level resolution

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 4

The distance between these two antennas thus corresponds to a diagonal extension of the two-dimensional area

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP4628924A1Radar behind license plate
Publication Date: 2025.10.08 APTIV TECHNOLOGIES AG
  • EP4628924A1 patent drawingFigure 1~2
  • EP4628924A1 patent drawingFigure 3~4
  • EP4628924A1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a radar system for automotive applications. The radar system comprises a multitude of radar antennas which are arranged on an enlarged two-dimensional area. The present disclosure further relates to a component of a car, in particular a front component of a car. The component comprises a radar housing, and a radar system supported by the radar housing.