Phase-Shifted Digital Conversion Circuit for Higher Signal-to-Noise Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional digital conversion circuits, such as frequency-to-digital converters, suffer from a decreased signal-to-noise ratio (SNR) due to the use of a single divided down signal as feedback, which results in significant SNR degradation, especially in high-band applications.
Innovation Solution
Generating multiple phase-shifted signals from a source signal, where each signal has a frequency that is a fraction of the original, and processing these signals through hard-limiting and detection circuits to improve SNR, allowing for differentiation of signals with 90-degree phase changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single divided down signal is used as feedback in a digital conversion circuit, then the device complexity is reduced, but the signal-to-noise ratio deteriorates
Solution Approach 1:
The patent divides the single feedback signal path into multiple parallel paths, where each path processes a different phase-shifted version of the source signal (e.g., 0°, 90°, 180°, 270° phases). This segmentation allows the system to process multiple signals simultaneously through separate hard-limiting and detection circuits, thereby improving the signal-to-noise ratio while maintaining manageable device complexity through modular architecture.
2Reliability
If multiple phase-shifted signals are processed through hard-limiting and detection circuits, then the signal-to-noise ratio is improved, but the device complexity increases
Solution Approach 1:
The patent merges the outputs of multiple detection circuits that process different phase-shifted signals. By combining these detection results, the system achieves improved signal-to-noise ratio through coherent integration of multiple signal paths. The merging process allows the system to leverage the information from all phase-shifted signals while managing the overall circuit complexity through integrated processing architecture.
3Device complexity
If conventional frequency-to-digital conversion is used with single signal processing, then the device complexity is low, but the measurement precision deteriorates
Solution Approach 1:
The patent employs periodic sampling of the source signal at multiple phase offsets (e.g., sampling at 0°, 90°, 180°, 270° phases in successive periods). This periodic action with phase diversity allows the system to accumulate measurement information from multiple cycles and phase points, thereby improving frequency measurement precision while keeping the conversion circuit complexity manageable through systematic periodic processing.
Data Source
AI summary
The signal-to-noise ratio for a digital conversion circuit is improved by taking a source signal and generating N signals that are each phase-shifted relative to each other, thereby generating N phase-shifted signals. Each of the N signals has a frequency that is a fraction of a frequency of the source signal. The source signal is input to a dividing circuit to generate the N signals. The source signal is generated by a signal source, such as an oscillator. Each of the N signals is hard-limited and processed through a detection circuit. The detection circuit can be a frequency detection circuit configured to determine the frequency of the source signal and to output a corresponding digital word, or a phase detection circuit configured to determine a phase of the source signal and to output a corresponding digital word.