Phase Rotator Calibration with Lookup-Table Pre-Distortion
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Solution Overview
Problem
Advanced automotive radar systems require high-speed and high-accuracy control circuits, but existing technologies face challenges in balancing performance targets with product costs, particularly in calibrating phase rotators effectively.
Innovation Solution
A phase rotator calibration system that includes a calibration circuit using an arccosine function to determine phase errors, storing these values in a look-up table for pre-distortion during normal operation, ensuring accurate phase rotation in radar systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sophisticated circuitry is used to meet performance targets, then measurement precision and reliability improve, but device complexity and product cost increase
Solution Approach 1:
The patent applies preliminary action by performing phase calibration measurements and storing correction values in lookup tables before normal operation. The calibration circuit pre-determines phase errors for various input phases and stores these values, eliminating the need for complex real-time calibration calculations during radar operation.
Solution Approach 2:
The patent uses copying by creating lookup tables that store pre-measured phase correction values. Instead of performing complex real-time calculations, the system copies and applies pre-determined correction values from the lookup tables based on the current input phase, significantly simplifying the operational circuit complexity.
2Measurement precision
If calibration accuracy is improved through detailed measurements, then measurement precision improves, but loss of time increases
Solution Approach 1:
The patent performs comprehensive phase calibration measurements in advance during a calibration mode, storing the results in lookup tables. This preliminary action allows the system to achieve high measurement precision without incurring time penalties during normal radar operation, as the calibration data is readily available for immediate application.
Solution Approach 2:
The patent implements periodic action by separating calibration operations from normal operation into distinct phases. The calibration circuit operates periodically to update lookup tables, while the main radar system operates continuously using pre-stored calibration data, minimizing interference and time loss.
Data Source
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AI summary
A phase rotator calibration system (100) is provided. The phase rotator calibration system (100) includes a phase rotator portion (120) having input for receiving an input signal (PHIN) and an output for providing an output signal (PHOUT). A calibration portion (140) is coupled to the phase rotator portion. The calibration portion is configured to determine a phase error (PHerr) based on a phase estimation (PHest). The phase estimation is generated by way of an arccosine function (130).