Parallel ADC Signal Splitting for Wide Dynamic Range Conversion

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Solution Overview

Problem

Existing broadband analog-to-digital converters face challenges in expanding dynamic range without generating interference, requiring complex calibration and high accuracy, and suffer from reduced measurement speed due to analog gain variations and pulse interference.

Innovation Solution

A device with a power divider splitting the analog input signal into two branches, each connected to an analog-to-digital converter, and an adaptive control device adjusts amplitudes to minimize interference and eliminate the need for calibration, using an adaptive filter to synchronize phases and amplitudes, and a switching mechanism to automatically handle overloads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a preamplifier with variable amplification factor is used to expand dynamic range, then the dynamic range is improved, but glitches and pulse interference are generated

Engineering Contradiction:
Improvedynamic rangeVSAvoidglitches and pulse interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The signal path is divided into multiple parallel branches, each with its own fixed-gain amplifier and ADC. The power divider splits the input signal into multiple paths (e.g., two branches with different power fractions), allowing simultaneous processing of different signal levels without switching or variable gain, thereby eliminating glitches and pulse interference while maintaining expanded dynamic range.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple analog-to-digital converters are used to improve dynamic range, then the dynamic range is improved, but device complexity increases

Engineering Contradiction:
Improvedynamic rangeVSAvoidnumber of converters required
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple ADC outputs from parallel branches are merged through a summing device with appropriate weighting. The digital signals from each branch are combined and equalized to produce a single output that benefits from the extended dynamic range of all branches without requiring separate processing chains, thereby reducing overall system complexity while maintaining the dynamic range improvements.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If analog gain is varied to adapt to signal levels, then the dynamic range is improved, but measurement speed is reduced due to settling time

Engineering Contradiction:
Improvedynamic rangeVSAvoidmeasurement speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically selects which parallel branch to use based on signal level conditions, with each branch optimized for specific signal ranges. The switching device automatically connects the appropriate branch (e.g., first branch for lower signals, second branch for higher signals) without requiring gain adjustment or settling time, thereby maintaining both expanded dynamic range and high measurement speed through instantaneous branch selection.

Inventive Principle:
Principle #15Dynamics

4Reliability

If dither signals are added to expand dynamic range, then the dynamic range is improved, but calibration requirements increase

Engineering Contradiction:
Improvedynamic rangeVSAvoidcalibration process requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses the inherent statistical properties of the parallel branch outputs to automatically determine optimal equalization weights. By analyzing the combined output statistics and adapting the weighting factors to maximize signal quality, the system performs self-calibration without requiring external calibration equipment or complex manual adjustment procedures, thereby achieving extended dynamic range while minimizing calibration complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2406886B1Device for converting high dynamic range analog signals to digital
Publication Date: 2013.06.19 ROHDE & SCHWARZ GMBH & CO KG
  • EP2406886B1 patent drawingFigure 1
  • EP2406886B1 patent drawingFigure 2

AI summary

The device of the present invention for digitalizing data comprises a power divider (5), having a first and second output (6, 7), wherein the power divider (5) divides an analog input signal (4) into a first analog signal(8) which can be output to the first output (6) of a first signal branch having a first power fraction, and into a second analog signal (9) which can be output to a second output (7) of a second signal branch having a second power fraction. Furthermore, the first and the second output (6, 7) of the power divider (5) are connected to a first and second analog-digital converter (12, 13) each, so that the first and second analog signal (8, 9) can be digitalized each. A switching device (33) connects either the first or the second signal branch to a signal output (34). A controller (24) is disposed between the second analog-digital converter (13) and the switching device (33) for adaptively adjusting at least the amplitudes of the second digital output signal (20) of the second analog-digital converter (13) to the amplitudes of the first digital output signal (19) of the first analog-digital converter (12).