Analog to Digital Conversion System Using Nyquist Zone Alignment
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Solution Overview
Problem
Conventional analog to digital converters struggle to simultaneously achieve a wide dynamic range and wide band, often requiring multiple converters with different optimizations, leading to circuit complexity and increased cost due to the need for multiple frequency converters.
Innovation Solution
The system employs a combination of analog to digital converters with different sampling frequencies and bit numbers, using a common frequency conversion means to produce digital data with a narrow dynamic range and wide band, and vice versa, aligning Nyquist zones to optimize performance and simplify RF circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single analog to digital converter is used to achieve wide band, then the sampling frequency must be high, but the dynamic range becomes narrow
Solution Approach 1:
The patent divides the signal processing into multiple parallel paths, each with dedicated ADCs optimized for specific sampling frequencies. The input signal is segmented and routed to different ADCs based on the required sampling rate, allowing simultaneous high-speed conversion and high-precision conversion without interference between the two functions.
Solution Approach 2:
The patent introduces a new dimension of signal routing and frequency conversion by inserting frequency converters between the input signal and ADCs. This allows the system to transform a single input signal into multiple frequency-shifted versions that can be processed by different ADCs, effectively adding a frequency dimension to the conversion architecture.
2Measurement precision
If multiple analog to digital converters are used to satisfy both wide dynamic range and wide band, then the circuit complexity increases due to multiple frequency converters
Solution Approach 1:
The frequency converters in the patent are designed to serve multiple functions: they perform frequency shifting for signal routing, enable multiple ADCs to process different frequency bands, and facilitate flexible signal distribution. This multi-functionality reduces the need for separate dedicated components for each function, thereby reducing overall circuit complexity.
3Adaptability or versatility
If multiple analog to digital converters with different sampling frequencies are used, then the dynamic range and band requirements can be met, but the cost increases
Solution Approach 1:
The patent employs frequency converters that can dynamically change the frequency parameters of the input signal before it reaches the ADCs. By adjusting the conversion frequency and selecting different sampling rate ADCs, the system can adapt to various bandwidth requirements using a standardized set of components, reducing the need for custom-designed converters for each application.
Data Source
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AI summary
While combining AD converters that one is wide band but narrow dynamic range and the other is narrow band but wide dynamic range, it allows settings to provide a common intermediate frequency signal to the AD converters. A first BPF 50 provides a first AD converter 54 with the output signal obtained by getting an intermediate frequency signal Sif through a first band in the second Nyquist zone of the first AD converter 54. A second BPF 52 provides a second AD converter 56 with the output signal obtained by getting the intermediate frequency signal Sif through a second band in the third Nyquist zone of the second AD converter 56. At this time, the second band is set in the center portion of the second Nyquist zone band, and the first band is set in the center portion of the band of the intermediate frequency signal.