UHF RFID Tag Antenna Mounted on Metallic Objects

A deployment method by changing the gap between a tag antenna and a metallic plate is given to reduce the metal effects on antenna. Pad some medium into the gap, and then integrate. By the adjustment of the gap's thickness, the reflection of the electromagnetic wave is full used to improve the antenna's gain and field strength. Thus may result in great read range. Finite element method (FEM) is used to simulate the tag's performance. Theory analyses are also given. With this method, the high performances of the tag can be available even in metal environments.