Due to the weak signal energy of the backscatter link,traditional RFID communication is easily affected by noises,interferences, and interceptions from the environment. To solvethe problem, a novel passive UHF RFID tag baseband processorenhanced with spread spectrum technique is presented in thispaper. In addition, power-saving strategies are proposed toreduce the power consumption of the tag. Simulated results showthat spread spectrum approach largely reduces the Bit ErrorRate and improves system’s reliability and security. Finally, acomplete RFID tag with the proposed baseband processor wasdesigned and fabricated using 0.18um 1P6M CMOS technology.From the measurement result, the overall power consumption ofthe baseband processor is about 8.8uW at the minimum voltageof 1.04V.