Body-Biased CCDD RF-DC Rectifier for Leakage and Area Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional RF-DC converters face challenges such as high reverse leakage current, threshold voltage effects, large ripple, and complex circuitry, which hinder efficient energy harvesting across a wide power dynamic range and require significant active area.
Innovation Solution
A body-controlled RF-DC converter employing a cross-coupled differential-drive (CCDD) rectifier with body biasing to control threshold voltage, utilizing fewer capacitors and transistors to achieve high power conversion efficiency and a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional rectifier circuits are used, then power conversion efficiency can be improved, but reverse leakage current and threshold voltage effects increase
Solution Approach 1:
The patent employs body biasing to dynamically control the threshold voltage of PMOS transistors, changing the electrical parameters to optimize performance. By adjusting the body voltage (Vb) relative to the source voltage, the threshold voltage (Vth) is modulated to reduce reverse leakage current while maintaining efficient rectification across varying input power levels
Solution Approach 2:
The rectifier circuit uses dynamic threshold voltage control through body biasing, where the body voltage is adjusted based on operating conditions. This dynamic adaptation allows the circuit to maintain optimal performance across a wide power dynamic range (20 dBm), transitioning between different operating modes to minimize losses
2Loss of energy
If conventional RF-DC converters are used, then power conversion efficiency can be improved, but circuit complexity and active area increase
Solution Approach 1:
The patent merges multiple functions into a single integrated rectifier stage. The cross-coupled differential-drive configuration combines rectification, impedance matching, and threshold voltage control in one compact circuit block, eliminating the need for separate feedback resistors and complex biasing networks required by conventional designs
Solution Approach 2:
The PMOS transistors in the cross-coupled configuration serve multiple functions simultaneously: rectification, signal coupling, and threshold voltage control through body biasing. This multi-functionality reduces the total component count and simplifies the overall circuit architecture while maintaining high efficiency
3Loss of energy
If conventional rectifier configurations are used, then power conversion efficiency can be improved, but active area occupancy increases
Solution Approach 1:
The body biasing control is nested within the existing rectifier structure, utilizing the body terminals of the PMOS transistors that are already present in the cross-coupled configuration. This nested approach adds threshold voltage control functionality without requiring separate control circuits or additional transistors, thus saving area
Solution Approach 2:
The patent achieves high efficiency rectification in a compact area by merging the rectifier and impedance matching networks into a single cross-coupled differential-drive stage. This integration eliminates the need for separate matching components and reduces the total active area to just 0.0054 mm²
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The RF-DC converter achieves a wide power dynamic range of 20 dBm and peak power conversion efficiency of 71.6% with a compact active area of 0.0054 mm², and up to 1.6 V output voltage with a three-stage design, outperforming conventional designs in efficiency and area efficiency.
Implementation Method 1
The antenna circuit is configured to receive radio frequency signals
Implementation Method 2
a first cross-coupled differential-drive (CCDD) rectifier stage
Data Source
AI summary
A radio frequency to direct current (RF-DC) converter for harvesting radio frequency energy includes an antenna circuit, and a pluarilty of cross-coupled differential-drive (CCDD) rectifier stage. The antenna circuit receives RF signals and outputs a positive signal at a positive RF terminal and outputs a negative signal output at a negative RF terminal. Each CCDD rectifier stage includes a first NMOS transistor, a first PMOS transistor, a second NMOS transistor and a second PMOS transistor. Each CCDD rectifier stage further includes two flying capacitors and two body capacitors. An input terminal is connected to a connection point between a source terminal of the first NMOS transistor and a source terminal of the second NMOS transistor. An 10 output terminal is connected to a connection point between a source terminal of the first PMOS transistor and a source terminal of the second PMOS transistor.