RF Receiver Noise Power Calibration Method
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Solution Overview
Problem
Modern wireless receivers face challenges in accurate calibration, particularly in achieving consistent gain and frequency response across varying conditions, due to the high costs and limitations of traditional calibration methods such as frequency-sweeping inputs and on-chip local oscillator signals, which can be expensive and less robust.
Innovation Solution
A method that predicts noise power at the input and output of an RF receiver to dynamically calibrate frequency and gain without additional hardware, using noise power analysis to determine calibration values, allowing for calibration during normal operation even when signal strength is below the noise floor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency-sweeping input tone is used for calibration, then gain and band tuning information can be obtained, but calibration cost becomes very expensive
Solution Approach 1:
The receiver uses its own internal noise sources to perform self-calibration, eliminating the need for external frequency-sweeping test equipment. The system measures its own noise power at different frequencies and uses this information to determine gain and band tuning characteristics autonomously.
Solution Approach 2:
Instead of using expensive external test signals, the invention creates an internal model by measuring the receiver's own noise output characteristics. This copied noise-based approach provides the necessary calibration information without requiring external test equipment.
2Ease of manufacture
If on-chip local oscillator signal is used for calibration, then calibration can be performed without external equipment, but calibration robustness decreases due to local oscillator power changes
Solution Approach 1:
The invention measures the actual noise power output of the receiver across different frequencies and uses this measured data to determine calibration parameters. This copied approach based on actual measurements is more robust than relying on theoretical local oscillator power levels, which can vary with temperature and other conditions.
3Adaptability or versatility
If dedicated calibration structures are included in integrated circuits, then calibration functionality is provided, but die area and design resources increase
Solution Approach 1:
The invention uses the existing receiver components (noise sources, amplifiers, frequency synthesizers) for dual purposes: normal signal reception and self-calibration. By making the calibration function universal and integrated into existing structures, no additional dedicated calibration hardware is required.
Solution Approach 2:
The receiver performs its own calibration using internally generated noise and existing measurement capabilities, eliminating the need for separate calibration circuits or structures. The system serves its own calibration needs through software-controlled measurement and adjustment.
4Adaptability or versatility
If narrowband response is implemented, then frequency selectivity is improved, but calibration accuracy becomes more critical and difficult to achieve
Solution Approach 1:
The invention measures the actual frequency response by analyzing noise power across different frequency bands and uses this measured data to accurately determine calibration parameters. This empirical approach based on actual measurements provides the precision needed for narrowband applications.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables accurate and cost-effective calibration of RF receivers, ensuring optimal performance across temperature and performance corners without the need for extra hardware, reducing design complexities and test costs.
Implementation Method 1
a frequency and gain calibration method which uses noise power
Data Source
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Figure 3A~3B
AI summary
A method calibrates a spread spectrum receiver having a received signal strength below a noise floor. The method includes estimating an input noise power, and measuring a noise power output from the receiver. The method also includes comparing the estimated input noise power with the measured output noise power to determine at least one calibration value. The method further includes calibrating the receiver based upon the at least one calibration value.