Driver Assistance Radar Beamforming for Grating Lobe Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radar systems with array antennas often suffer from grating lobes, which can incorrectly estimate or remove actual targets, leading to adverse effects on driver assistance functions due to the generation of ghost targets.
Innovation Solution
An apparatus and method that utilize a signal processor to generate a virtual antenna signal based on original signals received from a reception antenna, performing digital beam forming and side lobe suppression by synthesizing the original signal with a virtual antenna signal, effectively reducing side lobes through phase modulation and windowing processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If array antenna structure is used to increase angular resolution, then measurement precision is improved, but grating lobes are generated causing ghost targets
Solution Approach 1:
A virtual antenna signal is introduced as an intermediary to suppress grating lobes. The virtual antenna signal is generated by combining original reception signals with specific phase relationships, and this intermediary signal is then used in the beamforming process to cancel out grating lobe effects while preserving main lobe detection capability
Solution Approach 2:
The phase parameters of antenna elements are dynamically adjusted to create the virtual antenna signal. By changing the phase relationships between elements in the virtual antenna configuration compared to the physical antenna, the beam pattern is modified to suppress grating lobes while maintaining angular resolution
2Object-generated harmful factors
If grating lobe position is estimated and removed, then ghost targets are reduced, but actual targets may be lost due to incorrect estimation
Solution Approach 1:
The virtual antenna signal is generated in advance before beamforming, incorporating phase information that pre-configures the beam pattern to suppress grating lobes. This preliminary configuration ensures that when beamforming is performed, the grating lobes are already suppressed, eliminating the need for post-processing removal that could accidentally remove actual targets
3Device complexity
If conventional antenna arrangement is used, then device complexity is reduced, but side lobe suppression is insufficient
Solution Approach 1:
A virtual antenna array is created as a logical copy of the physical antenna array, but with different phase relationships between elements. This virtual copy is not a physical structure, so it adds minimal complexity, yet it enables effective side lobe suppression through the phase differences in the virtual element spacing
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 solution effectively suppresses side lobes, reducing the occurrence of ghost targets and improving the accuracy of target detection for driver assistance functions by minimizing the impact of grating lobes on radar beam patterns.
Implementation Method 1
The signal processor may generate the virtual antenna signal in combinations of phase components of original signals received from the receiver
Implementation Method 2
The signal processor may perform digital beam forming (DBF) on the original signal received from the receiver and perform DBF on the virtual antenna signal
Data Source
AI summary
Disclosed herein is an apparatus including a transmitter configured to transmit a signal through a transmission antenna, a receiver configured to receive a signal reflected from a target through a reception antenna and output the received signal as a digital signal, and a signal processor electrically connected to the transmitter and the receiver, wherein the signal processor generates a virtual antenna signal based on an original signal received from the receiver and suppress a side lobe of the original signal based on the virtual antenna signal.