ABSTRACT
This chapter considers the behavior of electromagnetic waves near metallic surfaces. It focuses on the effects of metallic surfaces on Radio frequency identification device (RFID) tag antennas. The chapter presents a few examples of passive Ultra High Frequency RFID tags suitable for attaching to metallic structures. One part of the electromagnetic theory that is related to the presence of metallic media in the environment should be mentioned. One issue that arises when placing an RFID tag near a metallic surface is the change of the tag antenna parameters such as the input impedance, directivity, radiation pattern, and the efficiency. Some of the biggest challenges when it comes to designing RFID tags for metallic objects are the size and cost of the tags. The RFID tag uses a design approach different from that of the earlier and utilizes the electromagnetic fields that are present near the metallic surface.
