RF Channel Calibration Using Internal Signal Loopback
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Solution Overview
Problem
Radio frequency channel phases in wireless devices change due to device aging and temperature variations, leading to inaccurate angle of arrival measurements and the need for calibration.
Innovation Solution
A wireless device with multiple radio frequency modules, where one module sends a calibration signal to be received by multiple antennas, allowing a processor to determine device phase differences and calibrate corresponding channels, considering antenna differences and distances, and storing these differences for future calibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dedicated hardware calibration instruments are used for radio frequency channel calibration, then calibration can be performed before device delivery, but the device complexity increases and calibration cannot be performed after delivery due to device aging and temperature changes
Solution Approach 1:
The patent implements self-calibration by having the wireless device use its own internal radio frequency modules and antennas to perform calibration without external instruments. The first radio frequency module sends calibration signals that are received by the second radio frequency module through multiple antennas, enabling the device to calibrate itself and eliminating the need for dedicated calibration hardware.
Solution Approach 2:
The patent makes existing radio frequency modules serve dual purposes: normal communication functions and calibration functions. The same radio frequency modules and antennas used for communication are also used for calibration, eliminating the need for dedicated calibration hardware and reducing device complexity.
2Reliability
If radio frequency channel calibration is performed using traditional methods, then calibration can be done before delivery, but calibration accuracy deteriorates after delivery due to device aging and temperature changes
Solution Approach 1:
The patent transforms calibration from a static, one-time pre-delivery process to a dynamic, on-demand process. The wireless device can perform calibration at any time after delivery by executing the calibration method, allowing adaptation to changing environmental conditions and device aging, thus maintaining long-term calibration accuracy.
3Measurement precision
If multiple radio frequency modules are used for calibration, then calibration accuracy is improved by considering antenna differences and distance differences, but the device complexity increases
Solution Approach 1:
The wireless device uses its own multiple radio frequency modules and antennas to perform mutual calibration. The first radio frequency module sends calibration signals that are received by the second radio frequency module, enabling the device to self-calibrate using its existing hardware resources without adding external calibration equipment.
Solution Approach 2:
The patent replaces physical measurement of antenna characteristics with signal-based phase difference measurement. Instead of mechanically measuring antenna positions and characteristics, the system uses radio frequency signals to measure phase differences, which are then used to calculate distance differences and compensate for calibration errors.
Data Source
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AI summary
Embodiments of the present invention provide a wireless device and a radio frequency channel calibration method, and relate to the field of communications technologies, so as to improve accuracy of radio frequency channel calibration. The wireless device includes a first radio frequency module, a second radio frequency module, and a processor. The first radio frequency module and the second radio frequency module operate on a same frequency band. The first radio frequency module is connected to a calibration antenna, and configured to send a calibration signal by using the calibration antenna. The second radio frequency module is connected to at least two to-be-calibrated antennas, and configured to receive the calibration signal by using each of the at least two to-be-calibrated antennas. The second radio frequency module corresponds to at least two radio frequency channels, the at least two radio frequency channels respectively correspond to the at least two to-be-calibrated antennas, and a quantity of the at least two radio frequency channels is the same as a quantity of the at least two to-be-calibrated antennas. The processor is configured to determine a device phase difference of each of the at least two radio frequency channels, and calibrate a corresponding radio frequency channel by using the device phase difference of each of the at least two radio frequency channels.