UHF RFID system has been mainly used in logistics,production and supply chain management. The implementation of UHF RFID reader with excellent performance is still challenging. This paper presents a UHF RFID reader implementation for EPC C1G2 protocol. EPC C1G2 physical layer architecture and some critical modules like encoder ,decoder, modulator and demodulator are described in details. All modules are verified in FPGA and the experiments demonstrate that the designed RFID reader baseband system could perform well.