Antennas for a battery-assisted RFID tag with thin and flexible film batteries

A design concept and some examples of antennas suitable for battery-assisted radio frequency identification (RFID) tag with a thin and flexible film battery are presented. For the antenna design of this kind of a battery-assisted RFID tag, a special caution is necessary considering the presence of a thin and flexible film battery. A very simple and easy way to design an antenna for such a tag is to place the film battery on some part of the antenna to avoid the influence or interference of it on the antenna performance. One reference antenna and two types of reduced-size antennas are designed based on this concept, and their performance on communication distance with a reader is compared experimentally. It is demonstrated by measurement that the normal read range with continuous reading is around 4.5–4.9 m and the maximum read range is 6–6.2 m between the reader and the battery-assisted RFID tags with three different antenna types. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 494–498, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23127