Multipath DAC Weight Switching for Low-Distortion Bandwidth Expansion
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Solution Overview
Problem
Existing multipath digital-to-analog (D/A) converters face inefficiencies in combining multiple digital data signals, particularly in handling different frequency bands and sampling rates, leading to interleave images and distortion products.
Innovation Solution
A multipath D/A converter design that utilizes input terminals for multiple digital signals, an analog signal combination unit with clock signal-driven weighting coefficients, and digital filters, where signals are combined by adding and subtracting during alternating clock signal periods, with coefficients differing between periods to optimize signal aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If multiple digital data signals are combined using conventional multipath D/A converters, then the bandwidth is increased, but interleave images and distortion products are generated
Solution Approach 1:
The patent applies periodic switching of weighting coefficients synchronized with the clock signal. During first half-periods, one set of coefficients is applied, and during second half-periods, a different set is applied. This periodic action allows the system to process multiple digital data signals at different sampling rates without generating interleave images and distortion products, while maintaining enhanced bandwidth output
Solution Approach 2:
The patent changes the weighting coefficients parameter dynamically based on the clock signal phase. By switching between different coefficient sets (e.g., from +1/-1 to -1/+1) during alternating half-periods, the system adapts to handle multiple input signals with different sampling rates, eliminating distortion while preserving bandwidth expansion
2Adaptability or versatility
If digital signals with different sampling rates are processed, then the adaptability is improved, but the device complexity increases
Solution Approach 1:
The signal combination unit is designed with universal functionality to handle multiple digital data signals with different sampling rates using a single unified architecture. By implementing periodic weighting coefficient switching, the same hardware structure can process various input configurations without requiring separate processing paths for each sampling rate, thus maintaining adaptability while controlling complexity
Data Source
AI summary
A multipath D/A converter is provided and has input terminals for a first and a second digital signal, and a signal combination unit D/A converting the digital signals supplied to the input terminals, and combining the generated analog signals. The signal combination unit includes a clock signal with a period having a first half period and a second half period. The signal combination unit combines the analog first and second signals by aggregating them with respective weighting coefficients. The signal combination unit has an output terminal for issuing an analog signal based on the aggregation. The signal combination unit applies a first set of weighting coefficients during the first half period of each period and a second set of weighting coefficients during said second half period of each period. The first set of weighting coefficients differs from the second set of weighting coefficients in at least one coefficient.