(12) United States Patent
Kodukula et al.
(io) Patent No.: (45) Date of Patent:
US 7,323,977 B2 Jan. 29, 2008
(54) TUNABLE RFID TAG FOR GLOBAL APPLICATIONS
(75) Inventors: Venkata S. Kodukula, Bothell, WA
(US); Pavel Nikitin, Seattle, WA (US);
For Sander Lam, Bothell, WA (US)
(73) Assignee: Intermec IP Corp., Woodland Hills,
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 271 days.
(21) Appl. No.: 11/081,239
(22) Filed: Mar. 15, 2005
An RF transponder comprises a transponder integrated circuit, an antenna connected to the transponder integrated circuit, and at least one parasitic element adapted to interact electrically with the antenna and thereby affect antenna impedance. The orientation of the parasitic element with respect to the antenna is selected to achieve a desired operational frequency band for the RF transponder. Specifically, the spacing between the antenna and the parasitic element is selected to achieve the desired operational frequency band. For example, a first selected spacing may enable an operational frequency band suitable for a first geographic region (e.g., the United States), a second selected spacing may enable an operational frequency band suitable for a second geographic region (e.g., Europe), and a third selected spacing may enable an operational frequency band suitable for a third geographic region (e.g., Japan).
38 Claims, 6 Drawing Sheets