A quadruple diversity receiver in the UHF RFID reader system

In this paper, we propose a new receiver scheme equipped with quadruple diversity capability in UHF-band RFID reader system. The quadruple diversity receiver outperforms the conventional I/Q diversity receiver by making use of additional signal paths. In particular, it is shown that the larger is the phase difference between the reader and the tag, the larger performance improvement we have. The performance of the proposed receiver scheme is demonstrated by computer simulations for various wireless channel environments.