The development of networking technology makes radio frequency identification (RFID) are paid more and more attention by people either inside or outside the field where ultra-high frequency radio frequency identification system (UHF RFID) for its identification distance, reading and writing speed advantages, becomes a focus on the development of RFID. RFID system generally consists of tags, readers and the host, readers and tags use non-contact coupling mode of information delivery. Reader is an important p...