Radar Subarray Spacing Asymmetry for Wide-Angle Directivity
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Solution Overview
Problem
Existing wide-angle radar devices face challenges in preventing the generation of unnecessary grating lobes and achieving a desired directivity pattern, particularly when using a subarray antenna configuration, which can lead to false detection and reduced performance in detecting targets like pedestrians and vehicles.
Innovation Solution
The radar device employs a configuration where the transmitting and receiving array antennas have subarray elements with a dimension larger than the predetermined antenna element spacing, and the absolute difference between the subarray element spacings of the transmitting and receiving array antennas is equal to the predetermined antenna element spacing, preventing grating lobe generation and ensuring a desired directivity pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If subarray elements are arranged with large spacing to accommodate their physical dimension, then the array antenna can be constructed, but grating lobes are generated on the directivity pattern
Solution Approach 1:
The patent transitions from a single-array configuration to a dual-array configuration (transmitting array and receiving array), utilizing the spatial relationship between two dimensions to eliminate grating lobes. By arranging subarray elements in both transmit and receive arrays with specific spacing relationships, the system achieves accurate directivity patterns without requiring uniformly small element spacing throughout.
Solution Approach 2:
The patent changes the spacing parameters of subarray elements between the transmitting and receiving arrays. Specifically, it sets the spacing of subarray elements in the transmitting array to be different from that in the receiving array, with the difference equal to a predetermined value. This parameter variation allows the system to accommodate larger element dimensions while preventing grating lobe generation.
2Device complexity
If the dimension of subarray elements is made larger than the predetermined antenna element spacing, then fewer elements are needed, but grating lobes are generated
Solution Approach 1:
The patent uses the dual-array configuration to resolve the contradiction between element size and grating lobe prevention. By distributing elements across two arrays (transmit and receive) with different spacing characteristics, the system can use larger element dimensions while maintaining directivity accuracy through the combined spatial arrangement.
Solution Approach 2:
The patent introduces asymmetry in the subarray element spacing between the transmitting and receiving arrays. The spacing in each array is deliberately made different, with their difference equal to a predetermined value. This asymmetric configuration allows larger element dimensions while preventing the symmetric grating lobe patterns that would otherwise occur.
3Measurement precision
If mechanical or electrical scanning is performed multiple times to achieve high resolution, then detection accuracy improves, but scanning time increases and following performance degrades
Solution Approach 1:
The patent replaces mechanical scanning with signal processing-based direction estimation. Instead of physically moving the antenna beam through multiple scanning positions, the system uses the array antenna structure combined with signal processing algorithms to estimate target direction from the received signals, dramatically reducing scanning time while maintaining detection resolution.
Solution Approach 2:
The patent creates a multi-functional system where the array antenna serves both transmission and reception functions, and where signal processing performs multiple tasks including direction estimation, target detection, and resolution enhancement. This eliminates the need for separate mechanical scanning operations while achieving high detection accuracy.
Data Source
AI summary
A radar transmitter transmits a radar signal through a transmitting array antenna at a predetermined transmission period, and a radar receiver receives a reflected wave signal which is the radar signal reflected by a target through a receiving array antenna. A transmitting array antenna and a receiving array antenna each include multiple subarray elements, the subarray elements in the transmitting array antenna and the receiving array antenna are linearly arranged in a first direction, each subarray element includes multiple antenna elements, the subarray element has a dimension larger than a predetermined antenna element spacing in the first direction, and an absolute value of a difference between a subarray element spacing of the transmitting array antenna and a subarray element spacing of the receiving array antenna is equal to the predetermined antenna element spacing.