Radar Phase Offset Calibration via Complex Signal Analysis
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Solution Overview
Problem
Current radar systems face challenges in accurately determining the azimuth of detected targets due to parasitic phase offsets between sum and difference channels, which hinder precise azimuth determination and evaluation of signal distortions using phase and amplitude monopulse methods.
Innovation Solution
A method for automated calibration of radar systems that involves determining the phase offset between sum and difference channels by analyzing the real and imaginary parts of the complex amplitude monopulse signal, allowing for compensation of relative phase shifts and enabling accurate azimuth determination without the need for manual adjustments or additional test signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual adjustment of phase shifter is used to calibrate the radar system, then the phase offset between sum and difference channels can be adjusted, but the calibration process becomes time-consuming and labor-intensive
Solution Approach 1:
The radar system performs self-calibration by automatically determining the phase offset between sum and difference channels using received signals from antenna elements. The system calculates the phase difference through signal processing without requiring manual intervention, thereby eliminating time-consuming manual adjustment while maintaining calibration accuracy.
Solution Approach 2:
The invention changes the calibration approach from manual phase shifter adjustment to automatic phase offset calculation based on signal parameters. By analyzing the phase relationship between signals from different antenna elements and computing the phase offset mathematically, the system achieves rapid calibration without manual intervention.
2Measurement precision
If manual calibration with test targets is performed, then phase alignment can be achieved, but the process requires additional equipment and operational complexity
Solution Approach 1:
The radar system uses its own received signals from antenna elements to determine the phase offset, eliminating the need for external test targets or additional calibration equipment. The system processes signals already present in the operational bandwidth to achieve phase alignment automatically.
Solution Approach 2:
The calibration method uses the same signal processing chain and antenna elements used for normal radar operation, making the calibration process universal and eliminating the need for separate calibration equipment. The system performs both calibration and operational functions using the same hardware resources.
3Ease of operation
If phase offset is not compensated, then the system operates without calibration, but azimuth determination accuracy deteriorates due to parasitic phase offsets
Solution Approach 1:
The system dynamically adjusts the phase parameter by calculating and compensating for the phase offset between sum and difference channels. This parameter correction is performed automatically using signal processing, maintaining azimuth determination accuracy without adding operational complexity.
Solution Approach 2:
The system determines the phase offset from received signals and applies compensation to correct the phase error. This feedback mechanism automatically maintains accurate azimuth determination by continuously monitoring and correcting phase relationships between channels.
Data Source
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AI summary
A method for calibrating a radar system (10) comprising a receiver unit (110) with a plurality of antenna elements (111, 112, 113) is described. The method comprises the following steps: receiving a first complex signal on a first channel (100) and converting the received first complex signal into a first complex information transmission signal; receiving a second complex signal on a second channel (200) and converting the received second complex signal into a second complex information transmission signal; determining a complex amplitude monopulse signal as the ratio of the first complex information transmission signal to the second complex information transmission signal;Determining a phase shift between the first complex information transmission signal and the second complex information transmission signal based on a real part and an imaginary part of the ratio of the first complex information transmission signal to the second complex information transmission signal; using the determined phase shift to compensate for a relative phase shift between the first complex information transmission signal of the first channel and the second complex information transmission signal of the second channel.