Passive Sensor Backscatter Wireless Energy Harvesting
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Solution Overview
Problem
Existing passive sensor systems require batteries or power sources, limiting their convenience, environmental impact, and operational lifetime, and do not efficiently enable continuous data collection and energy reception simultaneously.
Innovation Solution
A passive sensor network using backscatter communication and wireless energy emitters, where sensors operate at two distinct frequencies for data transfer and energy reception, eliminating the need for batteries and utilizing a microcontroller and semiconductor for modulation control, with a voltage multiplier for continuous power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If passive sensors use batteries or power sources, then they can operate continuously and transmit data, but the system complexity increases and environmental impact worsens due to battery disposal
Solution Approach 1:
The patent extracts the power source (battery) from the sensor system entirely. Sensors are designed to be completely passive, harvesting energy from ambient RF signals in the environment rather than relying on internal power sources. This eliminates battery replacement needs and reduces device complexity while maintaining continuous operation capability.
Solution Approach 2:
The sensor system serves itself by harvesting energy from the ambient RF environment. The sensors automatically collect and store energy from available radio frequency signals, eliminating the need for external power sources or battery replacements. This self-powered approach extends operational lifetime indefinitely while reducing environmental impact.
2Use of energy by moving object
If passive sensors communicate via backscatter, then power consumption is reduced, but data transmission capability is limited
Solution Approach 1:
The patent combines multiple functions into the passive sensor system: energy harvesting from RF signals, energy storage in supercapacitors, data sensing, and backscatter communication. By merging these functions, the system achieves both low power consumption and adequate data transmission capability, as the harvested energy suffices for both operation and communication.
Solution Approach 2:
The ambient RF signals serve multiple purposes: they provide the energy source for powering the sensors and can also serve as the communication carrier for data transmission. This multi-functionality allows the system to maintain both low power consumption and effective data transmission without requiring separate power and communication infrastructure.
3Productivity
If sensors operate at two distinct frequencies, then data transfer and energy reception can occur simultaneously, but device complexity increases
Solution Approach 1:
The patent segments the frequency spectrum into two distinct bands: one frequency (or band) dedicated to energy harvesting and another frequency (or band) dedicated to data communication via backscatter. This frequency segmentation allows simultaneous operation of both functions without interference, enabling continuous data collection while managing complexity through clear functional separation.
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
Enables continuous, battery-free operation with unlimited lifetime, reducing environmental impact and user costs, and allowing flexible deployment in various applications such as indoor climate control and agricultural monitoring.
Implementation Method 1
antenna for data communication and electromagnetic energy reception for obtaining electrical energy for powering said node
Implementation Method 2
a semiconductor that changes the reflection coefficient of the sensor in order to communicate with the reader
Data Source
AI summary
A passive sensor network constituted by a reader (5), wireless energy emitters (2), and fully passive sensors (1) is described. The passive sensors allow continuously the data collection and transfer thereof whenever requested by the reader, via backscatter at a frequency (4), and in parallel the reception of energy from the transmitters (3). Each sensor integrates an antenna, two impedance matching networks, a semiconductor, a microcontroller and one or more sensors that do not require the use of their own power supply or batteries. The reader (remote unit) initiates the communication process. This communication is achieved by sending radio frequency commands recognized by the passive sensors. These sensors, upon receiving the commands from the reader, initiate the back transmission of data according to the received command. The power transmitters are used to allow continuous power supply of the passive sensors.