Vehicle Radar Sensor Subgroup Phase Control

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Solution Overview

Problem

Existing radar sensors for motor vehicles require complex phased array antennas to achieve angular resolution, which increases the number of phase shifters needed and complicates the system.

Innovation Solution

A radar sensor design that uses a group antenna with subgroups where the phase difference between subgroups is varied to control the main radiation direction, allowing for angle determination with a single phase shifter, and can be applied to both transmitting and receiving antennas, simplifying the structure and reducing the number of required phase shifters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional phased array antennas are used to achieve angular resolution, then angle-resolving capability is improved, but device complexity increases due to the large number of phase shifters required

Engineering Contradiction:
Improveangular resolutionVSAvoidnumber of phase shifters
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The antenna array is divided into multiple sub-arrays, each with its own phase shifter. Instead of requiring a phase shifter for every individual antenna element, the segmentation allows groups of elements to share common phase control, significantly reducing the total number of phase shifters while maintaining angular resolution capability through controlled phase differences between sub-arrays

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from controlling phase at the individual element level to controlling phase at the sub-array level, effectively moving the control dimension from element-wise to group-wise. This dimensional change in the control architecture reduces complexity while preserving the essential phase control functionality needed for angle resolution

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

This approach enables angle-resolving capabilities with a simplified structure, reducing hardware complexity and improving directivity, while allowing for effective estimation of elevation angles and compensation for installation errors.

Implementation Method 1

The radar waves emitted by the two subgroups are superimposed to form a radar lobe whose main radiation direction depends on the respective phase difference

Methodology Applied
Scientific EffectSuperposition of electromagnetic waves: Interference

Implementation Method 2

the phase difference is then larger by a fixed amount, which typically on the order of 180°. With this phase difference of 180°, destructive interference is obtained on the normal

Methodology Applied
Scientific EffectPhase modulation of electromagnetic waves: Phase Modulation

Implementation Method 3

With this phase difference of 180°, destructive interference is obtained on the normal, so that the levels of the received radar echoes for objects lying on the normal are minimal

Methodology Applied
Scientific EffectDestructive and constructive interference: Interference

Data Source

PatentEP3039444B1Radar sensor for motor vehicles
Publication Date: 2019.10.23 ROBERT BOSCH GMBH
  • EP3039444B1 patent drawingFigure 1
  • EP3039444B1 patent drawingFigure 2~3
  • EP3039444B1 patent drawingFigure 4~5

AI summary

The invention relates to a radar sensor for motor vehicles, comprising: at least one group antenna (10), which is formed by a linear arrangement of antenna elements (12); a feeding device (16, 18, 20) for feeding transmission signals (S1, S2) having an adjustable phase relationship into the antenna elements (12); a control device (28) for controlling the feeding device; and an evaluating device (26) for evaluating received radar echos and for locating objects with angular resolution, characterized in that the group antenna (10) is divided into at least two non-nested sub-groups (10a, 10b), that the feeding device (16, 18, 20) is designed to feed in-phase transmission signals to the antenna elements (12) of each sub-group, while the transmission signals for the different sub-groups have an adjustable phase difference, that the control device (28) is designed to periodically change the adjustable phase difference from measurement cycle to measurement cycle in such a way that the transmission signals have a base phase difference (δ) in one measurement cycle and have a phase difference that differs from the base phase difference by a fixed amount in another measurement cycle, and that the control device (28) is also designed to adjust the base phase difference (δ) on the basis of the levels (P1, P2) of the received radar echos for the purpose of maximizing the level difference between the measurement cycles.