Direct RF DAC Current Paths for High-Linearity Signal Conversion
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Solution Overview
Problem
Existing digital-to-analog converters (DACs) face challenges in maintaining high linearity at high operating frequencies, particularly when converting digital signals to radio frequency (RF) signals, without the use of RF generators and mixers.
Innovation Solution
A DAC architecture that includes a current cell matrix with normal and alternative paths, where the alternative paths perform internal toggling based on digital data patterns to ensure uniform power consumption and enhance linearity, using a direct RF synthesis architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a DAC operates at high frequency in a direct RF synthesis architecture, then the RF signal generation capability is improved, but the linearity deteriorates
Solution Approach 1:
The patent segments the current path into multiple parallel paths (first normal path, second normal path, first alternative path, second alternative path) to distribute the signal flow. This segmentation reduces the burden on individual paths, maintaining signal integrity and linearity even at high operating frequencies by preventing any single path from becoming a bottleneck or source of distortion.
Solution Approach 2:
The patent applies local quality by assigning different functions to different paths: normal paths handle regular signal conversion while alternative paths are specifically designed to consume uniform power and generate complementary signals. This localized functional differentiation ensures that each path optimizes for its specific purpose, maintaining overall linearity while enabling high-frequency operation.
2Measurement precision
If normal paths control current cells based on digital signal patterns, then the signal conversion accuracy is improved, but the power consumption becomes non-uniform causing linearity degradation
Solution Approach 1:
The patent merges normal paths and alternative paths in parallel to work simultaneously. The alternative paths are specifically designed to consume uniform power and generate complementary signals that compensate for the non-uniform power consumption of normal paths. This merging creates a synergistic effect where the total power consumption becomes uniform while maintaining high signal conversion accuracy.
Solution Approach 2:
The patent converts the harmful effect of non-uniform power consumption in normal paths into a benefit by using alternative paths to generate complementary signals. The alternative paths intentionally consume uniform power and produce signals that compensate for the deficiencies of normal paths, transforming what would be a disadvantage into an advantage for improving overall linearity.
3Manufacturing precision
If alternative paths perform internal toggling to consume uniform power, then the linearity is improved, but the device complexity increases
Solution Approach 1:
The patent uses copying by creating alternative paths that replicate the basic structure of normal paths but with modified functionality. The alternative paths copy the essential circuit elements (latch circuits, XOR gates, current cells) and adapt them for internal toggling operations. This copying approach maintains design consistency and simplifies implementation while achieving the desired uniform power consumption and improved linearity.
Data Source
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AI summary
An apparatus configured to transmit and receive a radio frequency (RF) signal is provided. The apparatus includes a digital-to-analog converter (DAC) configured to convert a digital signal into an analog signal, a power amplifier configured to amplify the analog signal, and an antenna configured to output, as the RF signal, the amplified analog signal to the outside. The DAC includes a current cell matrix including a plurality of current cells configured to generate the analog signal, a plurality of normal paths configured to control the plurality of current cells to be turned on or off, based on the digital signal, and a plurality of alternative paths configured to selectively consume power, based on a pattern of the digital signal.