Printed folded dipole antenna design for rectenna and RFID applications

An approximate or engineering model for a modified, asymmetric strip folded dipole antenna is discussed. The modification consists of adding short-circuit strips in the folded dipole arms, thereby giving means for input impedance tuning. This tuning is necessary for directly matching the antenna to the complex input impedance of the rectifier that is connected to the antenna to form a rectifying antenna or rectenna. The engineering model, when implemented in software, results in fast calculation times and allows implementation in an optimization shell for automatic antenna synthesis. To be able to use the antenna/rectenna in close proximity to a metallic object, while maintaining its low profile, the antenna will be placed on a thin EBG structure. First analysis results are demonstrated.