High dynamic range analog to digital converter architecture
AssigneeGeneral Dynamics C4 Systems, Inc.
InventorBruce A. Fette
Life of this patent
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Abstract
An analog-to-digital converter (“ADC”) architecture as described herein utilizes a digital signal processor having suitably configured waveform prediction logic that can predict expected types of input signals. The ADC architecture subtracts the predictable signal components from the analog input signal prior to the analog-to-digital conversion, which extends the dynamic range of the ADC employed by the ADC architecture. In practice, the ADC architecture can subtract predictable strong signal components from an analog input signal such that the ADC can apply its available dynamic range to the remaining weak signal components.
Claims26
An analog-to-digital converter (“ADC”) architecture comprising:
- an ADC comprising a positive input for a composite analog signal having a predictable strong signal component combined with a weak signal component, a negative input for a second analog signal, and an ADC output, said ADC being configured to generate a first digital output at said ADC output, said first digital output being generated in response to said composite analog signal and said second analog signal, and said first digital output being a digital representation of the weak signal component;
- a processor having an input coupled to said ADC output, and having a first output for a digital adjustment signal, said processor comprising a waveform prediction module configured to determine predictable signal characteristics of said strong signal component, to generate a digital representation of the strong signal component for combining with said first digital output, and to generate said digital adjustment signal in response to said predictable signal characteristics;
- and
- a digital-to-analog converter (“DAC”) coupled between said first output of said processor and said negative input of said ADC, said DAC being configured to generate said second analog signal in response to said digital adjustment signal.
A communication system including an analog-to-digital converter (“ADC”) architecture, said communication system comprising:
- an amplifier having a positive input for a first analog signal, a negative input for a second analog signal, and an amplifier output, said amplifier being configured to generate an output signal at said amplifier output, said output signal being generated in response to said first analog signal and said second analog signal;
- an ADC having an ADC input and an ADC output, said ADC input being coupled to said amplifier output, and said ADC being configured to generate a first digital output at said ADC output, said first digital output being generated in response to said output signal;
- a processor having an input coupled to said ADC output, and having a first output for a digital adjustment signal, said processor comprising a waveform prediction module configured to determine predictable signal characteristics of said first analog signal, and to generate said digital adjustment signal in response to said predictable signal characteristics;
- and
- a digital-to-analog converter (“DAC”) coupled between said first output of said processor and said negative input of said amplifier, said DAC being configured to generate an analog adjustment signal in response to said digital adjustment signal, said second analog signal being derived from said analog adjustment signal.
An analog-to-digital conversion method comprising:
- obtaining a composite analog signal comprising a first signal component and a second signal component;
- subtracting an analog adjustment signal from said composite analog signal, resulting in an adjusted analog signal;
- generating a first digital output based upon said adjusted analog signal;
- determining predictable signal characteristics of said composite analog signal;
- generating a second digital output based upon said predictable signal characteristics;
- combining said first digital output with said second digital output to obtain a digital representation of said composite analog signal;
- and
- updating said analog adjustment signal in response to said predictable signal characteristics.
Dependencies are inferred from the claim text.