This paper proposes a new form of passive UHF RFID system which has high tag detection accuracy but lower costs than existing systems for wide-range RFID scenarios requiring greater flexibility. This new system concept consists of a central baseband controller and a remote antenna subsystem, connected using a twisted-pair cable. Baseband signals are transmitted over the twisted-pair cable during the inventory session, and the transmitted radio frequency (RF) signals are up and down converted in the antenna subsystem. – 88 dBm reader sensitivity is achieved with an active leakage cancellation block, showing little degradation in tag detection performance over a 300m of Cat5e cable between the controller and the antenna. An average leakage suppression of 36.9 dB can be achieved with a fixed transmission power of 26.5 dBm. Compared with conventional RFID systems using coaxial cables between the reader and antenna, the presented system is superior in terms of link distance, link cost, and installation flexibility.