| 摘要 |
A feed structure (18) and matching circuit (20) for inductively coupling an antenna (16) with an IC (22) in an RFID tag (10). The tag (10) includes first and second feed structures (26,28) coupled with the antenna (16), a first transmission line (30) coupling the feed structures (26,28), and a matching circuit (20) including a second transmission line (32) having a portion that is substantially parallel to and spaced apart from the first transmission line (30) such that the first and second transmission lines (30,32) inductively couple. Where two or more antenna elements (56,57) are used, the elements (56,57) are sufficiently loosely coupled by inductive coupling that they can operate at nearly the same frequency without forming a single resonant antenna. Thus, for example, different elements can operate at approximately 905 MHz and approximately 925 MHz, respectively, to effectively cover the FCC range of 900-930 MHz.
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