Nov 18, 2005German RFID tag and label manufacturer KSW Microtec has started production of a new dual-antenna design for its EPCglobal Class 1 Generation 1 and Generation 2 inlays. The company claims its new antenna, which it calls the Taurus, gives tags better short-range read-write performance.
According to the company, a version of the Taurus design operating at 915 MHz and suitable for the U.S. market will soon be available for Gen 1 and Gen 2 inlays.
The dual-antenna design has a small rectangular antenna located at the center of the tag for accurate, close-range inlay reading and encoding. The design's larger antler-shaped outer antenna is used when long-range reads are required—such as when tagged cases pass through RFID portals conforming to Wal-Mart and U.S. Department of Defense (DOD) mandates.
According to KSW, the small centric antenna ensures that individual inlays and tags can be addressed directly without interference from nearby inlays while being encoded. Therefore, the transponder responds to RF signals in different ways. The smaller antenna, wired to the IC, acts as an impedance-matching structure similar to an HF antenna. To get longer read ranges, the tag uses the larger outer antenna, constructed as a resonant structure and not wired to the IC. The larger antenna works in tandem with the smaller one when a greater read range is required. The smaller antenna's loop-shaped configuration provides directed near-field coupling (inductive coupling) for encoding the inlay. Moreover, shielding to the interrogator can be used to protect the entire surface of the resonant structure from the signal and suppress the far-field effect of the transponder.
Another advantage of its antenna design, says KSW, is that the RFID chip attached to it has reduced sensitivity against electrostatic discharge damage because discharge takes place on the resonant structure.
KSW expects to begin high-volume production of its new inlay designs at its Dresden, Germany, plant by the end of the year, with first shipments going out in January.
"Inlays will be available with a four-week lead time, although large orders will require lead times of six to eight weeks," says Antge Schaller, a KSW spokesperson.
KSW says it makes sense to target the U.S. market first with its new inlay design. "The U.S. market is more active than the European. We see around 70 percent of our current inlay sales in the U.S.," says Schaller. An 868 MHz version, suited for the European market, is under development and likely to ship in 2006.
Pricing for the new Taurus inlays will depend on order volume; in orders of more than just 1 million, a dual-antenna Taurus inlay will cost around $0.12 each. The company says it can deliver inlays made with just the centric antenna for use by RFID label converters capable of printing the inlay's outer antenna themselves, or it can supply complete dual-antenna inlays for RFID label converters looking to produce finished labels quickly.
KSW Microtec first announced its dual-antenna design in October, and says it filed patents relating to the design in the United States and Europe.
