MIMO Radar Array Spacing for Wide-Angle Grating Lobe Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The detection performance of MIMO radar systems is compromised by the antenna arrangement in the transmission and reception branches, which affects the ability to accurately detect objects at wider angles due to issues with side lobes and grating lobes, particularly when the antenna element size is 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 groups of antennas, allowing for a virtual reception array that expands the aperture length and reduces grating lobes, thereby improving angular resolution and detection performance. This is achieved by arranging transmission antennas with spacings that are integer multiples of a fundamental spacing in one direction and reception antennas with corresponding spacings in a perpendicular direction, ensuring the difference in spacings between groups enhances the main lobe's directivity and suppresses side and grating lobes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If antenna elements are arranged with larger spacing to reduce grating lobes, then angular resolution is improved, but the antenna array size increases
Solution Approach 1:
The patent transitions from one-dimensional antenna spacing considerations to two-dimensional array configuration. By arranging antennas in a 2D grid pattern with specific spacing relationships (dx in x-direction, dy in y-direction), the system achieves grating lobe suppression through multi-dimensional spatial filtering, resolving the contradiction between array size and angular resolution
Solution Approach 2:
The patent systematically varies the spacing parameters dx and dy to optimize performance. By setting specific relationships between these parameters (e.g., dx = dy, or dx = 2dy), the system achieves grating lobe suppression at different angular positions while maintaining compact array dimensions, thus resolving the size-resolution tradeoff
2Length of stationary object
If antenna elements are arranged with smaller spacing to reduce array size, then device compactness is improved, but grating lobes increase and detection performance deteriorates
Solution Approach 1:
The patent employs two-dimensional antenna array configuration where spacing in the x-direction (dx) and y-direction (dy) are independently optimized. This multi-dimensional arrangement creates a more complex spatial filtering pattern that suppresses grating lobes more effectively than one-dimensional arrangements, enabling compact array design without sacrificing detection performance
Solution Approach 2:
The patent allows asymmetric spacing configurations where dx ≠ dy, enabling optimization for specific detection scenarios. By making the spacing asymmetric, the system can suppress grating lobes in particular angular regions while maintaining overall compactness, thus improving detection performance without requiring uniformly large array dimensions
3Measurement precision
If transmission and reception antennas are arranged with specific spacing relationships, then grating lobes are suppressed and detection accuracy is improved, but the system complexity increases
Solution Approach 1:
The patent establishes specific parameter relationships (dx, dy spacing values and their ratios) that simplify the overall system design. By setting these parameters according to defined rules, the complex task of grating lobe suppression is reduced to parameter selection, making the system easier to design and implement while maintaining high detection accuracy
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.