Antenna Array Subarray Spacing for Radar False Detection Elimination
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Solution Overview
Problem
Radar systems face challenges in eliminating false detections due to angle ambiguity caused by sparse antenna element spacing greater than half-wavelength, leading to increased complexity and cost with dense arrays, and decreased angular resolution.
Innovation Solution
The design of an antenna array with two or more sub-arrays having different spacings between adjacent elements, processing reflected signals to distinguish actual angles from ambiguous ones by generating detection overlap and distribution uniformity metrics, and using a combined metric to identify corresponding detection points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If antenna elements are arranged at half-wavelength spacing over a wide aperture, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The antenna array is divided into multiple subarrays, each with different element spacings. This segmentation allows the system to achieve the angular resolution benefits of dense arrays while using fewer total elements, as each subarray contributes differently to the overall angle estimation capability.
Solution Approach 2:
Different subarrays have different local element spacings, creating local quality variations that help distinguish between actual targets and false detections. This non-uniform spacing strategy allows sparse arrays to achieve performance comparable to dense arrays by optimizing the local spacing characteristics of each subarray.
2Device complexity
If antenna elements are arranged with spacing greater than half-wavelength, then device complexity is reduced, but false detections increase due to angle ambiguity
Solution Approach 1:
The patent employs asymmetric element spacing within subarrays, where adjacent elements have different spacing distances. This asymmetry creates unique angle response patterns that help distinguish true targets from false detections, allowing sparse arrays to maintain high detection reliability without requiring dense element placement.
Solution Approach 2:
Instead of using uniform half-wavelength spacing throughout the array, the patent inverts the conventional approach by using non-uniform spacing greater than half-wavelength in certain subarrays. This inversion of the standard design paradigm enables the system to reduce element count while maintaining or improving detection accuracy through the unique phase relationships created by varying spacings.
3Device complexity
If sparse array is used over wide aperture, then device complexity is reduced, but measurement precision deteriorates due to angle ambiguity
Solution Approach 1:
The patent introduces an additional dimension of differentiation by varying the spacing patterns across multiple subarrays. This dimensional approach to array design allows the system to extract more angular information from fewer elements by utilizing the different spacing configurations of each subarray, effectively compensating for the reduced element count.
Solution Approach 2:
The patent changes the spacing parameter across different subarrays, with each subarray having distinct spacing values between adjacent elements. This parameter variation enables the system to achieve better angular resolution with sparse arrays by creating diverse phase responses that improve angle estimation accuracy without requiring increased element density.
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 effectively eliminates false detections by clustering ghost objects, allowing for accurate identification of real targets without the high complexity and cost of dense arrays, while maintaining a wide aperture for vehicle surroundings information.
Implementation Method 1
Radar systems and other sensors are increasingly used in vehicles (e.g., automobiles, trucks, farm equipment, construction equipment, automated factories) to obtain information about the vehicle and its surroundings.
Data Source
AI summary
A system and method to eliminate false detections in a radar system involve arranging an array of antenna elements into two or more sub-arrays with a spacing between adjacent ones of the antenna elements of one of the two or more sub-arrays being different than a spacing between adjacent ones of the antenna elements of at least one other of the two or more sub-arrays. The method includes receiving reflected signals at the two or more sub-arrays resulting from transmitting transmit signals from the antenna elements of the two or more sub-arrays, and processing the reflected signals to distinguish an actual angle from the radar system to an object that contributed to the reflected signals from ambiguous angles at which the false detections of the object are obtained. A location of the object is determined as a result of the processing.