MIMO Radar Antenna Group Layout for Lower Grating Lobes
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Solution Overview
Problem
The detection performance of MIMO radar systems is compromised by the arrangement of antenna elements in the transmission and reception branches, leading to suboptimal angular resolution and increased grating lobes due to the size of the antenna elements being greater than or equal to one wavelength.
Innovation Solution
The radar apparatus employs a configuration where the transmission array antenna and reception array antenna are arranged with specific spacings between antenna groups, forming a virtual reception array with interelement spacings of 0.5λ, which reduces grating lobes and enhances angular resolution without requiring antenna elements smaller than one wavelength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If antenna elements are made smaller to reduce grating lobes and improve angular resolution, then angular resolution is improved, but manufacturing difficulty increases and antenna element size becomes constrained
Solution Approach 1:
The patent transitions from considering only intra-group antenna spacing to optimizing both intra-group spacing (first spacing) and inter-group spacing (second spacing). By introducing the second spacing dimension between antenna groups, the system achieves 0.5λ effective interelement spacing in the virtual array without requiring physical antenna elements smaller than one wavelength, thus resolving the contradiction between angular resolution and manufacturing ease
Solution Approach 2:
The patent introduces antenna groups as intermediary structures. Each antenna group contains multiple antenna elements arranged with first spacing, and groups are arranged with second spacing. This intermediary grouping structure enables the creation of a virtual array with fine effective spacing (0.5λ) while maintaining practical physical antenna element sizes, thereby mediating between the requirements for high angular resolution and ease of manufacture
2Measurement precision
If antenna groups are arranged with larger spacing to expand aperture length, then angular resolution is improved, but detection coverage area decreases
Solution Approach 1:
The patent utilizes two-dimensional spacing optimization (first spacing within groups, second spacing between groups) to expand the effective aperture length without simply increasing the physical footprint. By arranging antenna groups with appropriate second spacing while maintaining compact first spacing within groups, the system achieves both wide aperture for high angular resolution and adequate detection coverage area
3Device complexity
If MIMO radar uses conventional antenna arrangement, then system complexity is reduced, but detection performance deteriorates due to grating lobes and poor angular resolution
Solution Approach 1:
The patent segments the antenna system into multiple antenna groups, where each group contains antenna elements arranged with first spacing, and groups are arranged with second spacing. This segmentation enables the formation of a virtual array with 0.5λ effective interelement spacing, significantly improving angular resolution and reducing grating lobes while maintaining practical system complexity through modular group structures
Data Source
AI summary
Each of the plurality of transmission antenna groups includes a plurality of transmission antennas that are disposed at second intervals in a first direction, and are disposed at fourth intervals each of which is an interval of an integral multiple of a third interval in a second direction. Each of the plurality of reception antenna groups includes a plurality of reception antennas that are disposed at fifth intervals in the first direction, and are disposed at sixth intervals each of which is an interval of an integral multiple of the third interval in the second direction. The difference between the second interval and the fifth interval is the first interval, and the difference between the fourth interval and the sixth interval is the third interval.