Design Methods for 3D RFID Antennas Located on a Conducting Ground Plane

Based on 2D meander line methods, $3\times 3\times 3$ point, symmetrical, 3D dipole antennas structure was investigated exhaustively to identify those configurations with the highest efficiency and lowest resonant frequency for a fixed length. Maximum efficiency and input impedance occurs when adjacent high current segments in the antenna are oppositely directed. The optimal antenna structure was compressed and the effect of a nearby conducting plane was investigated. The meander line structure greatly improves antenna performance with a resonant frequency of 498 MHz and an efficiency of 62% when located on a conducting ground plane.