Multi-Stage RF-DC Rectenna for Broadband Energy Harvesting
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Solution Overview
Problem
Existing radio frequency energy harvesting circuits face inefficiencies when operating outside optimal resonance frequencies and require high incident power, especially in urban environments with varying frequency bands, leading to suboptimal energy conversion and increased component count.
Innovation Solution
A multi-stage RF-DC conversion device with radio frequency filter, voltage shift, and rectification modules, allowing for efficient energy harvesting across multiple frequency bands with reduced component count and lower power requirements, enabling correct summation of DC voltages without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single rectenna is used for single frequency band recovery, then the device complexity is reduced, but the adaptability to different frequency environments deteriorates
Solution Approach 1:
The patent implements a universal rectenna structure that can operate across multiple frequency bands by integrating multiple rectification circuits with different resonance frequencies into a single device. Each rectification circuit is tuned to a specific frequency band (e.g., 900MHz, 1800MHz, 2.1GHz, 2.4GHz), allowing the device to function universally across diverse frequency environments rather than being limited to a single band.
2Productivity
If multiple rectennas are used in parallel for multi-frequency recovery, then the energy harvesting capability is improved, but the device complexity and component count increase
Solution Approach 1:
The patent merges multiple rectification circuits into a single integrated structure where the DC outputs of different frequency bands are summed together. Instead of using separate parallel rectenna networks, the invention combines multiple rectification stages (each tuned to different frequencies) into one unified device, reducing component count while maintaining the ability to harvest energy from multiple frequency bands simultaneously.
3Reliability
If Greinacher type rectifiers are used for multi-frequency recovery, then the DC summation is improved, but the minimum incident power requirement increases
Solution Approach 1:
The patent changes the circuit topology from Greinacher-type rectifiers to a different configuration that requires lower incident power to activate. The new structure modifies the voltage and current parameters throughout the circuit, allowing operation at lower power levels while still achieving reliable DC voltage summation from multiple frequency bands. This parameter change enables the device to function in environments with lower RF power density.
4Productivity
If series or differential interconnection topologies are used for DC summation, then the energy recovery is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the rectification function into independent modular circuits, each handling a specific frequency band. These modular segments can be independently designed, tested, and manufactured, then integrated into the final device. This segmentation approach simplifies manufacturing compared to complex series or differential interconnection topologies, as each module can be optimized separately while maintaining overall system performance.
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 solution achieves improved RF-DC conversion efficiency, reduced component count, and lower power requirements, enabling effective energy harvesting in diverse frequency environments, with enhanced performance compared to prior art, including Greinacher type rectifiers.
Implementation Method 1
a radio frequency filter module, connected to a first input node of said conversion stage, configured to filter one of said at least one radio frequency signal
Implementation Method 2
a voltage shift module, connected between a second input node of said conversion stage, said radio frequency filtering module and an intermediate node of said conversion stage, configured to move a voltage present at所述第一输入节点 onto所述中间节点
Implementation Method 3
a voltage rectification module, connected between所述中间节点,所述第二输入节点 and an output node of said conversion stage, configured to rectify the voltage of所述中间节点 and deliver a rectified voltage to所述输出节点
Data Source
Figure 1~3A
Figure 3B~4
Figure 5~6
AI summary
The invention relates to a device for converting radiofrequency energy into DC current, receiving as input at least one radiofrequency signal and generating as output a DC current able to power at least one load, comprising at least two conversion stages each comprising: a radiofrequency filtering module (411), connected to a first input node (E1) of the conversion stage, configured to filter the radiofrequency signal; a voltage shifting module (412), connected between a second input node (E2) of the conversion stage, the radiofrequency filtering module (411) and an intermediate node (A) of the conversion stage, configured to displace a voltage present at the level of the first input node (E1) onto the intermediate node (A); a voltage rectification module (413), connected between the intermediate node (A), the second input node (E2) and an output node (B) of the conversion stage, configured to rectify the voltage of the intermediate node (A) and to deliver a rectified voltage on the output node (B).