Multi-Antenna RF Energy Harvesting with Charge Pump Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy harvesting units for sensor nodes, particularly in IoT networks, rely heavily on batteries, which require regular maintenance and produce waste, leading to high costs and environmental impact, and there is a need for an efficient energy harvesting solution that can power all internal components without additional power sources.
Innovation Solution
An energy harvesting unit comprising multiple antennas, first charge pumps, a selection unit, a second charge pump, and a multiplexer, which optimizes energy harvesting by selecting the antenna with the highest output voltage and using a strong charge pump to power internal components, while utilizing weak charge pumps for detection and rectification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple charge pumps are used to handle different frequency bands, then the energy harvesting capability across different frequencies is improved, but the device complexity increases
Solution Approach 1:
The system segments the energy harvesting function by providing multiple first charge pumps, each optimized for specific frequency bands (e.g., 2.4 GHz, 5 GHz). Each antenna-charge pump pair forms an independent segment that can be selectively activated based on the detected frequency band, allowing the system to handle multiple frequencies without requiring a single complex charge pump design
Solution Approach 2:
The second charge pump serves multiple functions: it acts as the main energy harvesting charge pump when needed, and can also function as a replacement for any of the first charge pumps if they fail. The multiplexer provides universal switching capability to connect any antenna to any charge pump, creating a multi-functional system that can adapt to different operating conditions
2Device complexity
If a single strong charge pump is used for all antennas, then the device complexity is reduced, but the energy harvesting efficiency for specific frequency bands deteriorates
Solution Approach 1:
Each first charge pump is designed with local quality optimized for specific frequency bands (e.g., first charge pump for 2.4 GHz, second charge pump for 5 GHz). This allows each charge pump to have parameters specifically tuned for its designated frequency range, maximizing energy harvesting efficiency for that band without compromising other bands
Solution Approach 2:
The system dynamically selects which charge pump to use based on the detected frequency band and output voltage levels. The multiplexer enables dynamic reconfiguration of the circuit topology, switching between different charge pumps and antenna combinations to optimize performance for current operating conditions while maintaining simple individual pump designs
3Productivity
If the second charge pump is connected to all antennas simultaneously, then the energy harvesting capability is improved, but the power consumption increases
Solution Approach 1:
The system uses partial action by activating only the necessary charge pumps based on detected frequency bands and signal strengths. Rather than continuously operating all charge pumps connected to all antennas, the multiplexer enables selective activation of specific antenna-charge pump pairs, reducing overall power consumption while maintaining adequate energy harvesting capability for current operating conditions
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 enhances energy harvesting efficiency, reducing the need for batteries and minimizing waste, enabling continuous operation of low-power devices like IoT sensor nodes, beacons, and smart home switches, with improved power management and reduced power consumption.
Implementation Method 1
the first charge pumps are configured to rectify the signals received by said antennas
Implementation Method 2
a plurality of first charge pumps, wherein each of said first charge pumps is operatively coupled to one of said antennas
Data Source
AI summary
An energy harvesting unit includes a plurality of antennas configured to receive one or more signals and a plurality of first charge pumps, in which each of the first charge pumps is operatively coupled to one of the antennas, thereby forming pairs of antennas and first charge pumps. The energy harvesting unit also includes a selection unit configured to measure and compare output voltages of the first charge pumps and to select, from the antennas, a specific antenna. The specific antenna is coupled to the first charge pump that produces the highest output voltage. The energy harvesting unit also includes a multiplexer configured to couple the specific antenna selected by the selection unit to a second charge pump.