Some novel design for RFID antennas and their performance enhancement with metamaterials

In this presentation we discuss a number of UHF/RFID tag designs including the hybrid loop, dual crossed-dipoles, and the dual crossed-dipoles using an inductively coupled feed. We have carried out extensive parametric studies in the process of analyzing the characteristics of the above antennas, and have investigated several techniques, including meandering, for size-reduction of these antennas. A design methodology based on the genetic algorithm (GA) is presented for the optimization of conformal antennas with electromagnetic bandgap (EBG) surfaces to improve the antenna performance. The EBG characteristic is realized by utilizing a frequency selective surface (FSS) placed above a thin dielectric substrate backed by a metallic ground plane to act as an artificial magnetic conductor (AMC). The antenna is then placed above the EBG surface to create the integrated EBG conformal antenna.