UHF RFID reader front-end having wideband and stable Tx/Rx isolation characteristic

A UHF RFID reader front-end structure having wideband and stable transmit/receive isolation characteristic is proposed. The proposed structure consists of a wideband balanced coupler and 4-port feed antenna system. The wideband RFID reader front-end has a high isolation feature insensitive to load variations. The transmit/receive isolation characteristic is achieved for UHF RFID band (860–960 MHz). The proposed structure has an isolation of more than 45 dB in the UHF RFID band according to the variations in matching and mutual coupling. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2467–2473, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25501

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