RF Coupler Measurement Accuracy via Offline Calibration
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Solution Overview
Problem
Current radio frequency equipment measurement systems face inaccuracies due to interference from unwanted reverse and forward signals, leading to false alarms or missed real alarms in measuring reflection coefficients and voltage standing wave ratio (VSWR), which complicates the calibration and operation of radio frequency equipment.
Innovation Solution
The method involves obtaining forward and reverse measurement signals during runtime, using a coupler to determine the reflection coefficient at a measurement reference plane, and subsequently calculating the reflection coefficient at a calibration reference plane, thereby improving measurement accuracy without requiring additional hardware or complex algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional measurement methods are used to measure reflection coefficient and VSWR, then the measurement process is simple, but the measurement accuracy deteriorates due to interference from unwanted reverse and forward signals
Solution Approach 1:
The measurement process is segmented into two distinct phases: offline calibration phase where interference characteristics are pre-measured and stored, and online measurement phase where only the actual reflection coefficient is calculated using the pre-obtained interference data. This segmentation allows complex interference compensation to be performed once during calibration, rather than continuously during operation, thereby improving measurement accuracy while maintaining operational simplicity.
Solution Approach 2:
The interference signals from unwanted reverse and forward signals are pre-measured and characterized during an offline calibration phase before actual operation. The calibration data including interference characteristics are stored for later use. This preliminary action eliminates the need for complex real-time interference analysis during online measurement, improving measurement accuracy without increasing operational complexity.
2Measurement precision
If offline calibration is performed to compensate for interference, then measurement accuracy is improved, but the calibration process becomes more complex
Solution Approach 1:
The measurement system performs self-calibration by automatically measuring its own interference characteristics during the offline calibration phase. The system uses internal couplers and signal paths to characterize the interference from unwanted reverse and forward signals without requiring external calibration equipment. This self-service approach improves measurement accuracy while simplifying the calibration process by eliminating the need for complex external calibration apparatus.
3Productivity
If runtime measurement is performed, then the measurement is performed during operation, but the CPU load increases due to complex calculations
Solution Approach 1:
The computational workload is segmented between offline calibration phase and online measurement phase. During offline calibration, complex interference characteristics are pre-calculated and stored. During online runtime measurement, only simple calculations using the pre-stored calibration data are required. This segmentation enables runtime measurement (improving productivity) while minimizing CPU load during operation by moving heavy computational tasks to the offline phase.
Solution Approach 2:
All complex computational tasks for interference compensation are performed in advance during the offline calibration phase. The calibration data including compensation factors and interference characteristics are pre-computed and stored in memory. During runtime measurement, the system only needs to retrieve and apply the pre-computed data, dramatically reducing CPU load while maintaining measurement efficiency.
Data Source
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AI summary
Embodiments of the present disclosure relate to a method and an apparatus of measurement, a radio frequency equipment and a computer-readable medium. One embodiment of the method comprises: during the runtime of a radio frequency equipment, obtaining, by a coupler in the radio frequency equipment, a forward measurement signal from a first radio frequency device to a second radio frequency device of the radio frequency equipment and a reverse measurement signal from the second radio frequency device to the first radio frequency device; determining, based on the forward measurement signal, the reverse measurement signal and offline calibration data, a reflection coefficient at a measurement reference plane between the coupler and the second radio frequency device; and determining, based on the reflection coefficient at the measurement reference plane, a reflection coefficient at a calibration reference plane between the second radio frequency device and a load of the radio frequency equipment. In this way, there is no need to add too more hardware circuits, thereby saving hardware cost, and there is no need to add a complex real-time running algorithm, thereby reducing the CPU load and further ensuring the measurement accuracy.