Electromagnetic Environment of UHF-RFID

The number of applications that use radio-frequency identification (RFID) technology has grown continually in the last few years. In this presentation we will present the results of research on the electromagnetic environment on RFID systems. We analyze the effects of UHF MHz China RFID system near a GSM frequency bands. Kurokawa´s method of calculating the power reflection coefficient from the Smith chart in the situation is applied to passive RFID tag design. The performance analysis of a specific RFID tag is presented to be compared with the theory. One of our objectives has been to examine tag designs that are less sensitive to their environment, in that their radiation patters and tag response characteristics change little when placed on different distance and orientation. We introduce a technique for deploying RFID systems and engineering solutions based on fundamental electromagnetic understanding. The paper will also explore tag designs that use electromagnetic models to simulate and engineer RFID systems.