Transmit/Receive Isolator for UHF RFID Reader with Wideband Balanced Directional Coupler

摘要

A wideband balanced directional coupler for UHF RFID reader is proposed. The wideband balanced coupler has a high isolation feature insensitive to load variations. The transmit and receive isolation characteristic is achieved for UHF RFID band (860～960 MHz). The proposed structure has an isolation of more than 45dB in the UHF RFID band according to the variations in matching.