RFID Reader Interference Signal Spatial Control
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Solution Overview
Problem
Existing methods for reading RFID tags simultaneously or in close proximity often result in unintended activation of tags outside the desired area, leading to unpredictable results and lack of spatial control.
Innovation Solution
The method involves transmitting an interference signal to block command signals from reaching target RFID tags, followed by an interrogation signal to allow only the target tags within a specific range to respond, thereby enabling selective reading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single reader device transmits interrogation signals to activate numerous RFID tags simultaneously, then productivity is improved, but spatial control deteriorates causing unintended activation of tags outside the desired area
Solution Approach 1:
The patent introduces an interference signal as an intermediary element that mediates between the reader's interrogation signal and the RFID tags. This interference signal selectively blocks command signals from reaching non-target tags while allowing target tags to receive and process commands, thus enabling simultaneous reading with spatial control
Solution Approach 2:
The patent applies local quality by creating different signal conditions in different spatial zones. The interference signal is transmitted only in specific areas where unintended tag activation occurs, leaving other areas unaffected. This allows the system to maintain high productivity while providing localized spatial control to prevent unwanted tag responses
2Object-affected harmful factors
If directional antennas are used to localizing RFID interrogation signals, then spatial control is improved, but device complexity increases
Solution Approach 1:
Instead of using complex directional antenna systems, the patent employs an interference signal as a simpler intermediary mechanism. This interference signal can be generated using standard omnidirectional antennas and provides the necessary spatial selectivity through signal processing rather than complex antenna geometry
Solution Approach 2:
The patent changes the approach from physical antenna configuration to signal parameter control. By adjusting the timing, frequency, and power levels of the interference signal, the system achieves spatial control without modifying the physical antenna structure, thereby reducing device complexity
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 approach provides improved spatial control over RFID tag population readings, ensuring that only tags within the desired location are read while ignoring those outside the range.
Implementation Method 1
transmitting an interference signal to block command signals from reaching target RFID tags
Implementation Method 2
The tag receives the signal, and responds by modulating the signal and then 'backscattering' an information response signal to the reader
Data Source
AI summary
A method and device enables reading radio frequency identification (RFID) tags in a localized area. The method according to one embodiment includes commencing transmission of an interference signal from a reader device (step 505). A command signal is then transmitted from the device while the interference signal is still being transmitted (step 510). The command signal instructs non-target RFID tags to not respond to an interrogation signal, and the target RFID tags do not process the command signal because the command signal is blocked by the interference signal. Transmission of the interference signal from the device is then stopped (step 515). The interrogation signal is then transmitted from the device after the interference signal is no longer being transmitted (step 520). Finally, a response signal is received at the device from the target RFID tags that enables the device to read only the target RFID tags (step 525).