Mixer-Free RF A/D Converter With Phased LNA Feedback
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Solution Overview
Problem
Low-power wireless receivers face challenges in reducing current consumption while maintaining linearity and blocking performance, with existing designs like super-regenerative receivers exhibiting poor performance in these areas.
Innovation Solution
A mixer-free RF analog-to-digital converter that directly converts RF input to a digital output stream using a single-bit or multi-bit quantizer, with a low-noise feedback signal provided to a noise shaping loop filter, allowing for a highly digital and low-power receiver architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If regenerative receiver or super-regenerative receiver designs are used to reduce current consumption, then power consumption is reduced, but linearity and blocking performance deteriorate
Solution Approach 1:
The patent replaces traditional analog receiver architectures (regenerative, super-regenerative) with a highly digital RF receiver architecture. The RF front-end includes an RF amplifier followed by an RF sampler that directly samples the RF signal, converting it to digital domain early in the signal chain. This substitution of digital processing for analog signal conditioning achieves lower power consumption while maintaining or improving linearity and blocking performance through digital signal processing techniques.
Solution Approach 2:
The patent changes the fundamental operating parameters of the receiver by operating the RF sampler at a sampling frequency at least twice the RF input signal frequency, enabling direct RF-to-digital conversion. The architecture uses a single-bit or multi-bit quantizer with noise shaping feedback, changing the quantization and feedback parameters to achieve high-resolution digital output from the RF domain, thereby resolving the trade-off between power consumption and performance.
2Use of energy by moving object
If the number of analog stages is reduced to create a more digital receiver, then power consumption is reduced, but signal processing capability may deteriorate
Solution Approach 1:
The patent substitutes analog signal processing stages with digital signal processing operations. The RF sampler and quantizer convert the RF signal directly to digital form, eliminating the need for multiple analog stages (mixers, filters, amplifiers). Digital signal processing then performs all necessary signal conditioning, filtering, and demodulation in the digital domain, maintaining full signal processing capability while dramatically reducing power consumption and improving linearity.
Data Source
AI summary
Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.