Platform-tolerant Design for an RFID Tag Antenna

In this paper, the previous design of an inductively-coupled feed for an RFID tag antenna is modified to realize a platform-tolerant characteristic. In the new feed, parts of the feed line are connected directly to the radiating element to realize a platform-tolerant RFID tag antenna, which comprises a microstrip patch. Since there is a ground plane underneath the patch and the feedline, the performance of the tag is essentially independent of the surface upon which the tag is mounted. This desirable feature of the tag is confirmed by the measured results presented herein.