Near-Field Miniature Coupler
First Claim
1. An RFID system for selectively communicating with a targeted transponder from among a group of multiple adjacent transponders, the RFID system comprising:
- a transponder conveyance system adapted to transport at least one targeted transponder from a group of multiple adjacent transponders through a transponder encoding region;
a transceiver configured to generate a communication signal, wherein the transceiver defines a source impedance; and
a near-field coupler in electrical communication with the transceiver for receiving the communication signal, the near-field coupler defining an input impedance and including,a grounded terminating load for substantially matching the input impedance to the source impedance, anda conductive strip for a transmission of an electromagnetic signal within an operating frequency range into the transponder encoding region, the conductive strip defining a length that is less than or substantially equal to a quarter wavelength of a center frequency of a operating frequency range.
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Accused Products
Abstract
A near-field coupler for a RFID system is provided. The coupler is configured to selectively communicate with a targeted transponder from among a group of multiple adjacent transponders. The coupler includes a conductive strip terminated by a load. The load is for matching an input impedance of the coupler to a source impedance of a transceiver. The conductive strip is based on a quarter wavelength of the center operating frequency. The conductive strip may have a substantially constant width and a length substantially equal to the quarter wavelength. Or the conductive strip may have a variable width defining a tapered profile and a length less than the quarter wavelength. The tapered profile may be an exponential profile or a Klopfenstein profile. Due to the overall size of the coupler to a typical transponder, the center of the coupler and the center of the transponder may be offset during coupling.
51 Citations
18 Claims
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1. An RFID system for selectively communicating with a targeted transponder from among a group of multiple adjacent transponders, the RFID system comprising:
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a transponder conveyance system adapted to transport at least one targeted transponder from a group of multiple adjacent transponders through a transponder encoding region; a transceiver configured to generate a communication signal, wherein the transceiver defines a source impedance; and a near-field coupler in electrical communication with the transceiver for receiving the communication signal, the near-field coupler defining an input impedance and including, a grounded terminating load for substantially matching the input impedance to the source impedance, and a conductive strip for a transmission of an electromagnetic signal within an operating frequency range into the transponder encoding region, the conductive strip defining a length that is less than or substantially equal to a quarter wavelength of a center frequency of a operating frequency range. - View Dependent Claims (2, 3, 4, 5)
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6. An RFID printer-encoder for printing and programming a series of media units wherein at least one of the media units includes at least one transponder, the RFID printer-encoder comprising:
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a printhead for printing indicia onto the series of the media units; a media conveyance system for transporting the series of media units including the transponder along a feed path and to the printhead and a transponder encoding region; a transceiver for generating a communication signal; and a coupler for receiving the communication signal and creating an electromagnetic field into the transponder encoding region, wherein a center of the coupler is offset from a center line of the feed path. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A RFID system adapted to provide selective communication between a transceiver and a targeted transponder disposed among multiple adjacent transponders and in a transponder encoding region, wherein the targeted transponder includes an antenna that defines a first length, the RFID system comprising:
a near-field coupler structured to receive at least one communication signal from the transceiver and further configured to create an electromagnetic field substantially concentrated in a near-field region of the coupler and into the transponder encoding region, wherein the near-field coupler defines a second length that is substantially equal to or less than one half the first length defined by the antenna of the targeted transponder. - View Dependent Claims (13, 14, 15, 16, 17, 18)
Specification