Receiver Signal Path Using Dual ADC Selection for Higher Bit Resolution
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Solution Overview
Problem
Existing methods for improving bit resolution in A/D converters, such as input voltage sharing and sub-ranging, face practical limitations due to the need for multiple A/D converters and high-performance additional devices, which are not feasible for wide-band signals like 20 GS/s, and are hindered by noise and high-frequency signal characteristics.
Innovation Solution
A receiver device configuration using two A/D converters with an amplifier and a digital signal processing unit that compares and selects outputs to enhance bit resolution without increasing the number of converters, employing an amplitude comparison unit and selector to determine valid digital signals from both converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the input voltage sharing method is used to improve bit resolution, then the bit resolution increases, but the number of required A/D converters doubles for each bit improvement
Solution Approach 1:
The patent combines the outputs of multiple A/D converters through digital signal processing to achieve improved bit resolution. Specifically, it uses a selection combiner that selects and combines digital signals from multiple A/D converters based on signal quality metrics, thereby achieving resolution improvement without requiring a proportional increase in the number of converters as traditional methods would demand.
Solution Approach 2:
The patent introduces a selection combiner as an intermediary component that processes and combines the outputs of multiple A/D converters. This intermediary performs digital signal processing to select the best signal segments from different converters and combine them to achieve improved resolution, avoiding the need for complex analog combining circuits or excessive numbers of converters.
2Measurement precision
If the sub-ranging method is used to double bit resolution, then the bit resolution improves, but high-precision D/A converters and additional devices are required
Solution Approach 1:
The patent extracts the essential function of resolution improvement by separating the A/D conversion process into multiple parallel channels that can be independently processed. Instead of using complex sub-ranging methods with D/A converters and subtraction circuits, it extracts digital signals from multiple A/D converters and processes them digitally to achieve the same resolution improvement with simpler hardware.
Solution Approach 2:
The patent replaces the mechanical/analog system of sub-ranging methods (which requires D/A converters, subtraction circuits, and amplifiers) with a digital signal processing approach. By performing the combination and selection operations in the digital domain rather than the analog domain, it eliminates the need for high-precision D/A converters and complex analog circuitry.
3Measurement precision
If additional devices such as D/A converter, subtraction circuit, and amplifier are used, then the bit resolution can be improved, but noise and high-frequency signal characteristics degrade the improvement effect
Solution Approach 1:
The patent replaces the analog signal processing chain (amplifiers, subtraction circuits, D/A converters) with digital signal processing. By performing all combination and selection operations in the digital domain after A/D conversion, it eliminates the introduction of noise and degradation from high-frequency signal characteristics that plague analog processing methods.
Solution Approach 2:
The selection combiner acts as a digital intermediary that processes signals after they have been converted to digital form, avoiding the noise-introducing analog components. It selects and combines digital signals based on quality metrics without requiring high-frequency analog signal processing, thereby eliminating the harmful effects of noise and signal degradation.
Data Source
AI summary
Provided is a receiver device including a first A/D converter (203), a second A/D converter (204), an amplifier (205) which is provided at a previous stage of the second A/D converter (204), and a digital signal processing unit (207). The digital signal processing unit (207) includes an amplitude comparison unit (211) configured to compare an amplitude of a digital signal output from the first A/D converter (203) and an amplitude of a digital signal output from the second A/D converter (204) to make a determination, and to output a determination result, and a selector (212) configured to select one of the digital signal output from the first A/D converter (203) or the digital signal output from the second A/D converter (204) based on the determination result.