Radar Device Fast Fourier Transform Beam Combining
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Solution Overview
Problem
Existing radar devices employing transmission changeover digital beam forming (DBF) systems face increased operation amounts due to the inability to use fast Fourier transform when virtual receiving elements are arranged at irregular intervals, leading to inefficient beam forming and signal processing.
Innovation Solution
A radar device that utilizes fast Fourier transform in the beam combining process, incorporating a Fourier transform section to extract and process received signals, a phase compensation section to correct phase differences, and a coherent integration section to combine signals from multiple transmitting elements, thereby reducing operation amounts and signal processing scale.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transmission changeover DBF system is used to improve angular resolution with small number of elements, then beam width is narrowed and angular resolution is improved, but operation amount increases and processing complexity increases when virtual receiving elements are arranged at irregular intervals
Solution Approach 1:
The patent segments the beam forming process into distinct stages: signal extraction from specific transmitting elements, Fourier transform processing, phase compensation for path differences, and coherent integration. This segmentation allows each stage to be optimized independently, reducing overall processing complexity while maintaining angular resolution improvements.
Solution Approach 2:
The patent changes the processing approach by applying fast Fourier transform instead of general discrete Fourier transform, and introduces phase compensation parameters to account for path length differences. These parameter changes enable efficient processing of irregularly arranged virtual receiving elements while maintaining measurement precision.
2Length of moving object
If transmission changeover DBF system is used to increase equivalent aperture, then beam width is narrowed, but operation amount increases from N2 to N log N ratio when using fast Fourier transform
Solution Approach 1:
The patent replaces the general discrete Fourier transform mechanism with the fast Fourier transform algorithm, which reduces computational complexity from O(N²) to O(N log N). This substitution maintains the ability to increase equivalent aperture while dramatically improving processing efficiency.
3Measurement precision
If virtual receiving elements are arranged at irregular intervals to improve beam forming capability, then angular resolution is improved, but fast Fourier transform cannot be used and operation amount increases
Solution Approach 1:
The patent introduces phase compensation as an intermediary step between signal extraction and Fourier transform processing. This intermediary compensates for the irregular spacing of virtual receiving elements, enabling the use of fast Fourier transform while maintaining the angular resolution benefits of irregular arrangements.
Data Source
AI summary
To provide a radar device which employs fast Fourier transform in a beam combining process to reduce the operation amount, the radar device including: a Fourier transform section that extracts a received signal that is obtained from waves radiated from a same transmitting element and received by a receiving element, and subjects a signal series of the extracted received signal to Fourier transform to generate a signal of a spatial frequency domain; a phase compensation section that compensates the signal of the spatial frequency domain with a phase difference that is caused by a difference between a predetermined reference position and a position of the used transmitting element; and a coherent integration section that adds the signals of the spatial frequency domain after the signals have been subjected to the phase compensation processing, which are obtained with the plurality of transmitting elements, in each of the spatial frequencies.