Multi-DAC Signal Conversion for High-Bandwidth Analog Output
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Solution Overview
Problem
Current digital-to-analog converters (DAC) have limited bandwidth and existing high-bandwidth conversion methods, such as time interleaving and bandwidth interleaving, require complex and costly high-frequency switches or non-linear analog band mixers that deteriorate the output signal.
Innovation Solution
A system and method utilizing multiple digital-to-analog converters with different but overlapping frequency ranges, phase-coherent signal paths, and analog filters to produce a high-bandwidth analog output signal without the need for analog mixers, using low-pass and band-pass filters for signal combination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If time interleaving is used to achieve high bandwidth, then bandwidth is improved, but device complexity increases due to requiring very precise high frequency switches
Solution Approach 1:
The invention divides the high-bandwidth signal conversion task into multiple parallel signal paths, each handling a specific frequency range with a dedicated DAC operating at a lower sampling rate. This segmentation allows each DAC to operate within its optimal performance range while collectively achieving the desired high bandwidth without requiring complex high-frequency switching.
2Speed
If bandwidth interleaving is used to achieve high bandwidth, then bandwidth is improved, but signal quality deteriorates due to non-linearities in analog band mixers
Solution Approach 1:
The invention replaces the mechanical/analog mixing approach with a digital signal processing approach. Instead of using analog band mixers that introduce non-linearities, the invention uses digital signal paths with phase-coherent DAC outputs that are combined without analog mixing, thereby maintaining signal quality while achieving high bandwidth.
3Speed
If analog mixers are used for signal combination, then bandwidth is improved, but signal quality deteriorates due to non-linearities
Solution Approach 1:
The invention extracts and removes the analog mixing stage from the signal path entirely. By taking out the analog mixer component, the system eliminates the source of non-linearities while maintaining the ability to achieve high bandwidth through parallel digital signal paths with phase-coherent DAC outputs.
Data Source
AI summary
A system for converting a digital input signal into an analog output signal is provided, the system has at least three different signal paths with different but overlapping frequency ranges, at least three digital-to-analog converters, at least three analog filters, and a combiner unit. Each of the digital-to-analog converters is connected to at least one signal path, wherein the signals transmitted to the digital-to-analog converters are phase coherent. Each of the digital-to-analog converters is connected to a combiner unit, and each of the analog filters is associated with one of the digital-to-analog converters, wherein at least one of the digital-to-analog converters has a lower sampling rate than the sampling rate of at least two others of the digital-to-analog converters. Further, a method for converting a digital input signal into an analog output signal is shown.