RFID Systems Using Twisted Pair Cables for Extended Range
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Solution Overview
Problem
The limited range of UHF RFID systems due to signal attenuation in coaxial cables restricts the separation between RFID reader hardware and antennas, and standard Ethernet interfaces hinder collaborative operation of multiple antennas.
Innovation Solution
The system employs twisted pair cables to transmit RFID signals at lower frequencies, allowing for longer transmission distances and alternative network topologies, with RF frontends integrated in antenna units and coordinated signal alignment by a central controller, enabling multiple antennas to operate collaboratively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If coaxial cables are used to transmit RFID signals, then signal transmission quality is maintained, but the separation distance between reader hardware and antennas is limited to approximately 10 meters due to signal attenuation
Solution Approach 1:
The patent replaces the traditional coaxial cable transmission system with a twisted pair cable system operating at lower frequencies. This substitution allows signals to be transmitted over much longer distances (up to 150 meters) while maintaining signal integrity, effectively resolving the contradiction between transmission distance and signal attenuation that plagues coaxial cable systems.
Solution Approach 2:
The patent changes the operating frequency parameter of the RFID system to lower frequencies when using twisted pair cables. This parameter change reduces signal attenuation in the cable medium, enabling transmission over distances up to 150 meters while maintaining adequate signal quality, thus resolving the distance-attenuation contradiction.
2Length of stationary object
If standard Ethernet interfaces are used for antenna connections, then long transmission distances are enabled, but accurate time information transmission is not readily available preventing collaborative operation of multiple antennas
Solution Approach 1:
The patent introduces a specialized interface layer between the Ethernet infrastructure and the RFID antenna system. This intermediary component captures precise timing information from the Ethernet signals and makes it available to multiple antenna subsystems, enabling them to operate collaboratively with accurate time synchronization despite using standard Ethernet for long-distance connections.
3Area of stationary object
If multiple antennas are deployed to extend coverage area, then wider area coverage is achieved, but signal coordination and time alignment between antennas becomes complex
Solution Approach 1:
The patent implements a feedback mechanism where a central controller receives timing and status information from multiple antenna subsystems and coordinates their operation. This feedback loop enables the system to automatically adjust signal timing and power levels across multiple antennas, simplifying the coordination complexity while maintaining wide coverage area through collaborative antenna operation.
Data Source
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AI summary
A system for the distribution of RFID signals to a remote antenna or a remote antenna network comprising: a central control module to generate signals and control the protocol operations; cable, in particular twisted pair cable, connecting the central module to one or more antenna subsystems carrying substantially baseband representations of the reader to tag modulation and tag to reader modulation.