Time-Interpolation ADC for High-Speed Direct RF Sampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Analog-to-digital converters for direct radio-frequency sampling receivers face challenges in operating at high speeds without requiring a mixer or local oscillator, and existing solutions often involve complex hardware and power-consuming components.
Innovation Solution
The proposed solution involves an analog-to-digital converter with first and second comparators and an interpolation comparator, which operate in the time domain using differential comparators for high-speed time-based interpolations, eliminating the need for a mixer and reducing hardware requirements through a multiplexing architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional mixers and local oscillators are used for RF signal conversion, then frequency conversion capability is improved, but hardware complexity and power consumption increase
Solution Approach 1:
The patent extracts and eliminates the mixer and local oscillator components from the traditional RF receiver architecture. By using direct RF sampling with time-interpolation comparators, the frequency conversion function is achieved through digital processing rather than analog mixing, thereby removing complex hardware while maintaining adaptability.
Solution Approach 2:
The patent replaces the mechanical/analog mixing system with a digital time-interpolation system. The frequency conversion that traditionally required analog mixers and local oscillators is now achieved through digital comparators that perform time-based interpolation on directly sampled RF signals, substituting complex analog mechanics with simpler digital processing.
2Adaptability or versatility
If traditional mixers and local oscillators are used for RF signal conversion, then frequency conversion capability is improved, but power consumption increases
Solution Approach 1:
The patent removes the power-consuming mixer and local oscillator components from the system. Frequency conversion capability is maintained through digital time-interpolation comparators that operate with lower power consumption compared to traditional analog mixing components.
Solution Approach 2:
The patent employs simple comparator circuits that can be rapidly switched and reset for each sampling interval. These comparators perform the frequency conversion function temporarily and are then reset, using minimal power for each conversion operation compared to continuously operating analog mixers and local oscillators.
3Productivity
If high-speed operation is required for direct RF sampling, then conversion speed is improved, but timing precision becomes more difficult to maintain
Solution Approach 1:
The patent segments the timing measurement process into multiple discrete time intervals using a time-interpolation architecture. By dividing the conversion process into sequential time slots with dedicated comparators, the system achieves high conversion speed while maintaining precise timing measurement through the segmented time-based interpolation approach.
Solution Approach 2:
The patent transitions from voltage-based comparison to time-based comparison, adding a temporal dimension to the conversion process. By measuring the time at which RF signal crossings occur rather than comparing voltage levels directly, the system achieves both high speed and high timing precision through time-domain sampling and interpolation.
Data Source
AI summary
A method of converting an analog signal to a digital code, comprising: using a first comparator to receive an input signal and a first comparison signal, and to generate a first output as a function of the input signal and the first comparison signal; using a second comparator to receive the input signal and a second comparison signal, and to generate a second output as a function of the input signal and the second comparison signal; and using an interpolation comparator to receive the first and second outputs, and to generate a third output based on relative timing of the first and second outputs; further including multiplexing to permit a second-level comparator to receive timing signals from the interpolation comparator and only one of two dummy comparators.