RFID tag using a surface insensitive antenna structure

Abstract

A surface-insensitive antenna system for use in an RFID tag having a wireless communication device includes a conductive tab coupled to the wireless communication device for receiving and radiating radio frequency energy. At least two of the fins are substantially identical in shape and are connected to the wireless communication device at a feed point, the feed point being positioned differently on each of the two fins, The width of the at least two fins taken along a direction transverse to the longitudinal center axis of each fin varies with the distance along the longitudinal center axis of each fin. Alternatively, the wireless communication device is connected to the fin at a feed point, the feed point being positioned differently on each of the fins, wherein each unit length along the longitudinal central axis of each fin The conductive area varies with distance along the longitudinal central axis.

Description

technical field [0001] The present invention relates to the field of radio frequency or radio frequency identification (RFID) tags and labels, and in particular to tags and labels including surface insensitive antenna structures. Background technique [0002] Current stocking and manufacturing methods rely on the ability to track and identify items of interest, such as inventory items, packages, individual parts, etc., and also rely on the ability to wirelessly communicate required item information for easy handling and use. One known method of tracking and providing desired item information is to attach wireless communication devices, such as active or passive transponders, to such items, thereby incorporating identification marks or tags capable of responding to radio frequency interrogations or commands. The tag may store or represent information about the attached item, such as a unique identification number, item status (eg, opened or unopened), location, and the like. ...

AI Technical Summary

Problems solved by technology

The problem with such encapsulated RFID tags is that they are cumbersome, expensive, difficult to install, and protrude from the surface of the package to which they are installed, making them susceptible to damage and dropping during handling of the package, leaving the item unidentified

[0007] To overcome the problems described above, the RFID embodiments that have been developed have been to adhere or print the tag directly onto the package surface, resulting in a lower tag profile that is less likely to be damaged or dropped during handling of the package

However, direct surface mounting of these antennas or tags makes their efficiency susceptible to variations in the dielectric properties of the attached surface

Therefore, these systems require different markings to be used on different packages, thereby adding cost, complexity, and inconvenience to manufacture

Since each stored item is preferably individually labeled, many different labels are required, creating further problems

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