RF Energy Collection Circuit for Passive RFID Read Range Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Passive RFID systems have limited read ranges due to the need for powerful interrogator signals to activate and power the RFID tag, making it difficult to remotely detect assets beyond 65 to 100 feet, and there is a need for systems that can report asset location and tampering information from several miles away while being concealable and resistant to damage.
Innovation Solution
The development of an RF energy collection circuit with a low-loss front end, a rectifier circuit, and an energy storage circuit that harnesses power from the RF environment using a folded dipole antenna in composite material and meta-material dielectrics, allowing the RFID system to extend its read range by minimizing activation energies and using narrow conductance band frequency-selective antennas to reduce transmission line losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If powerful interrogator signals are used to activate and power the RFID tag, then the tag can be activated and powered, but the signal path losses increase and the read range is limited to 65 to 100 feet
Solution Approach 1:
The patent converts the harmful signal path losses into beneficial stored energy by capturing ambient RF energy from the environment using wideband antennas and storing it in energy storage circuits. This harvested energy then powers the RFID tag, transforming the previously harmful loss into a useful power source that extends read range to several miles.
2Ease of operation
If the RFID system is made concealable with planar structure, then it can be hidden in container walls, but the device complexity increases to integrate energy harvesting and storage components
Solution Approach 1:
The patent merges multiple functions into a single planar structure: the RFID tag circuitry, wideband energy harvesting antennas, rectifier circuits, and energy storage circuits are all integrated into one concealed device. This consolidation allows the system to be hidden in container walls while maintaining all necessary functions for remote asset monitoring.
3Ease of manufacture
If passive RFID systems are used without internal power sources, then maintenance needs are avoided, but the read range is limited and activation energy requirements increase
Solution Approach 1:
The patent enables the passive RFID system to serve itself by harvesting ambient RF energy from the environment to power its own operations. The wideband antennas capture RF energy, which is rectified and stored in energy storage circuits, providing self-powered operation that eliminates the need for batteries while extending read range and reducing activation energy requirements.
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
This solution enables passive RFID systems to extend their read range up to 10 miles, reduce power losses, and maintain concealability, allowing for remote reporting of asset status with improved power efficiency and reduced device size, while minimizing signal path losses and enhancing system integrity.
Implementation Method 1
an RF energy collection circuit with a low-loss front end, a rectifier circuit, and an energy storage circuit that harnesses power from the RF environment using a folded dipole antenna in composite material and meta-material dielectrics
Implementation Method 2
a rectifier circuit coupled to receive coherent RF energy from the front end
Implementation Method 3
an energy storage circuit coupled to receive energy from the rectifier circuit
Data Source
AI summary
An R.F. energy collection circuit, provides a low-loss R.F. front end tuned to minimize lost power in R.F. bands commonly used for communications for passing substantially coherent R.F. signals received therefrom, a rectifier circuit coupled to receive coherent R.F. energy from the front end, and an energy storage circuit coupled to receive energy from the rectifier circuit.