Three-Channel Automotive Radar Antenna Array for Angular Resolution
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Solution Overview
Problem
Conventional two-channel automotive radar systems using small and inexpensive antennas suffer from complex phase relationships and ambiguities due to interactions with vehicle structures, leading to unacceptable angular resolution and phase distortion.
Innovation Solution
A three-channel automotive radar system is introduced, where a first antenna is spaced λ/2 from a second antenna, and a third antenna is spaced λ from the second antenna, with the first and third antennas sharing a receiver channel through a switch, generating two distinct phase curves to resolve ambiguities and improve angular resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If small and inexpensive antennas are used in a two-channel automotive radar system, then cost and size constraints are satisfied, but phase relationship complexity and angular resolution deteriorate due to interactions with vehicle structures
Solution Approach 1:
The patent divides the antenna system into three separate antenna elements instead of using two antennas. This segmentation allows the system to overcome the limitations of small antenna interactions with vehicle structures by distributing the measurement function across multiple elements, thereby improving angular resolution while maintaining cost-effectiveness through the use of simpler individual antenna components
Solution Approach 2:
The patent transitions from a two-channel system to a three-channel system by adding another antenna element. This dimensional change in the signal processing space (from 2D to 3D phase curve analysis) enables the system to resolve ambiguities that cannot be resolved in the original two-channel configuration, thereby improving angular resolution without requiring larger or more expensive antennas
2Reliability
If two antennas spaced by λ/2 are used in a conventional two-channel system, then unambiguous angle information over 180° FOV is theoretically achieved, but phase ripple and ambiguities occur in real world applications due to RF energy interactions with antenna surroundings
Solution Approach 1:
The patent changes the antenna spacing parameters from the conventional λ/2 spacing to specific non-uniform spacings (first antenna to second antenna: λ/2; second antenna to third antenna: λ; first antenna to third antenna: 3λ/2). This parameter change creates a three-channel system with phase curves having different slopes, which resolves the phase ripple and ambiguity problems that occur in conventional two-channel systems while maintaining reliable unambiguous angle information
3Measurement precision
If a three-channel switched antenna system is implemented, then angular resolution and azimuth angle resolution are improved, but device complexity increases due to the switch and additional antenna
Solution Approach 1:
The patent combines multiple antenna elements (three antennas) to share receiver channels, where the first antenna is coupled to a first receiver channel and the second and third antennas share a second receiver channel through a switch. This merging approach improves angular resolution by utilizing multiple spatial samples while managing complexity through shared receiver resources rather than requiring completely separate processing paths for each antenna
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 provides unambiguous angular information, higher azimuth angle resolution, reduced sensitivity to placement and mounting, and enhanced field of view performance by using two phase curves with different slopes, effectively addressing the limitations of conventional systems.
Implementation Method 1
As is known in the art, some existing automotive radar systems detect targets which produce a radar return signal having a signal strength which exceeds a threshold signal strength in range/Doppler space
Implementation Method 2
the phase difference between the signals in the two channels provides angle information which can be used to detect targets in an azimuth plane
Data Source
AI summary
Described herein is an automotive radar system which utilizes a three channel switched antenna to improve the angular resolution of an azimuth tracking two-channel, radar.