Radar Device Angle Measurement Using Sum and Difference Signals
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Solution Overview
Problem
Radar devices with small subarray antennas can experience errors in angle measurement due to the occurrence of grating lobes in the antenna pattern, leading to inaccurate target positioning.
Innovation Solution
The radar device incorporates an angle measurement unit that utilizes both sum signals and difference signals generated by sum and difference signal generation units to perform a beamformer angle measurement, effectively reducing the expansion of errors caused by grating lobes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the number of element antennas in subarray antennas is reduced due to arrangement constraints, then the device complexity is reduced, but grating lobes occur in the antenna pattern causing angle measurement errors to increase
Solution Approach 1:
The invention divides the distributed array antenna into multiple subarray antennas, each with a small number of element antennas. By segmenting the overall antenna system into manageable subarrays, the patent enables practical implementation with constrained element counts while maintaining angle measurement capability through combined processing of sum and difference signals from all subarrays.
Solution Approach 2:
The invention combines sum signals and difference signals from multiple subarray antennas to form a composite signal processing approach. This composite method leverages both signal types to achieve accurate angle measurement despite the limitations of small individual subarray configurations that produce grating lobes.
2Ease of manufacture
If small subarray antennas are used, then the ease of manufacture is improved, but the reliability of angle measurement deteriorates due to grating lobe interference
Solution Approach 1:
The invention introduces sum signals and difference signals as intermediary processing steps between the small subarray antennas and the final angle measurement. These intermediary signals serve as mediators that transform the limited subarray outputs into reliable angle information, compensating for the grating lobe effects inherent in small antenna configurations.
Solution Approach 2:
The invention changes the processing parameters by utilizing both sum and difference signal components rather than relying on a single signal type. This parameter change in the signal processing domain compensates for the physical limitations of small subarray antennas, maintaining measurement reliability despite manufacturing constraints.
3Device complexity
If grating lobes are present in the antenna pattern, then the device complexity remains low, but the precision of target positioning deteriorates due to expanded error distribution
Solution Approach 1:
The invention converts the harmful effect of grating lobes into a beneficial processing opportunity. By deliberately forming both sum and difference signals that incorporate the grating lobe patterns, the patent transforms what would be pure interference into useful information that, when processed together, actually improves angle measurement accuracy and target positioning precision.
Data Source
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AI summary
Multiple subarray antennas (1-1) to (1-N) each having multiple element antennas, multiple sum signal generation units (3-1) to (3-N) respectively connected to the multiple subarray antennas (1-1) to (1-N), for each generating a sum signal of signals of the multiple element antennas which each of the subarray antennas (1-1) to (1-N) has; multiple difference signal generation units (4-1) to (4-N) respectively connected to the multiple subarray antennas (1-1) to (1-N), for each generating a difference signal of the signals of the multiple element antennas which each of the subarray antennas (1-1) to (1-N) has; and an angle measurement unit (14) for performing a beamformer angle measurement on a target by using the sum signals generated by the multiple sum signal generation units (3-1) to (3-N) and the difference signals generated by the multiple difference signal generation units (4-1) to (4-N) are included.