Multi-loop bridge HF RFID reader antenna for improved positioning

This paper proposes a novel bridge-loop reader antenna for HF RFID with an aim to improve positioning accuracy when used for localizing moving objects on a tagged floor. The bridge-loop antenna provides additional information in form of error potential that can estimate displacement between antenna and a detected tag which helps to improve positioning. The effects of metallic objects on the antenna recognition area as well as impedance matching are also considered. Our simulation and experimental results show that the proposed bridge-loop antenna be able to produce variation in error potential when the reader moves over a tag allowing to estimate their relative positions. In addition to increasing positioning accuracy, it allows lower tag density.