System and Method for Selective Communication with RFID Transponders

Abstract

A system having an RFID transceiver is adapted to communicate exclusively with a single RFID transponder located in a predetermined confined transponder target area. The system includes a magnetic coupling device comprising a magnetic flux generator responsive to a radio frequency input signal and a magnetic field pattern former. The pattern former is configured to collect flux produced by the flux generator and to form a field pattern in the location of the transponder target area. The system establishes, at predetermined transceiver power levels, a mutual magnetic coupling which is selective exclusively for a single transponder located in the transponder target area.

Description

BACKGROUND OF INVENTION [0001] 1. Field of the Invention [0002] The invention relates to RFID communication systems which are selective for an individual transponder located in a predetermined target area, to the exclusion of other transponders, and to printers and other larger systems having such RFID communication systems. [0003] 2. Description of Related Art [0004] Inductively coupled radio frequency identification (RFID) technology allows data acquisition and or transmission from and or to active (battery powered) or passive RFID transponders using RF magnetic induction. To read or write from and or to an RFID transponder, the RFID transponder is exposed to an RF magnetic field that couples with and energizes the RFID transponder through magnetic induction and transfers commands and data using a predefined “air interface” RF signaling protocol. [0005] When multiple RFID transponders are within the range of the same RF magnetic field they will each be energized and attempt to com...

AI Technical Summary

Benefits of technology

"The invention relates to a system and method for selectively interrogating RFID transponders in a common RF magnetic field without using anti-collision management technologies. The system includes a printer and an RFID interrogator that can print and read from RFID transponders on media in close proximity to each other, without the need for additional shielding or separation. The system uses a magnetic coupling device that selectively communicates with a single RFID transponder on a carrier substrate, while ignoring other transponders in the same area. The invention aims to minimize costs and complexity by reducing the size and form factor of the required RFID transponder and by allowing for close spacing of the transponders without increasing the cost of the media or the printer. The invention can be used in printers that print on RFID transponder-mounting media in close proximity to the transponder, without requiring additional shielding or separation. The system also allows for selective communication with individual transponders on a roll or other format in which the transponder is attached."

Problems solved by technology

When multiple RFID transponders are within the range of the same RF magnetic field they will each be energized and attempt to communicate with the transceiver, potentially causing errors in reading and or writing to a specific RFID transponder.

However, anti-collision management increases system complexity and cost.

Further, anti-collision management is blind.

It cannot recognize where a responding transponder is located in the RF magnetic field.

This requires that the individual transponders have cumbersome shielding or a significant physical separation.

The extra carrier substrate increases materials costs and the required volume of the RFID media bulk supply for a given number of RFID transponders.

Having increased spacing between RFID transponders may also slow overall throughput.

When the size or form factor of the utilized RFID transponder is changed, the RF shielding and or anechoic chamber configuration may also require reconfiguration, adding cost and complexity and reducing overall productivity.

This may be very difficult to accomplish if the transponder must be interrogated in a shielded housing or chamber.

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