A Multi-Carrier UHF Passive RFID System

The "Gen2 " specification for UHF passive RFID system released by EPCglobal has become an intense research interest. A Gen2 tag derives its power from the RF wave emitted by a Gen2 RFID reader and responds its modulated backscatter signals to the reader. Due to the large propagation loss, the accessible range of a Gen2 tag is hence limited. Moreover, the readability of a Gen2 tag is often influenced by the multipath fading problem. In this paper we propose a multi-carrier UHF passive RFID system that can effectively extend the accessible range of a Gen2 tag. In addition, we investigate the multi-band backscatter property of Gen2 tags, which can be utilized to mitigate the multipath fading problems