Abstract: For the increasingly important application of RFID technology, some influencing factors on identification distance of passive backscatter RFID systems are studied systematically based on theories of electromagnetic radiation and microstrip antenna. Moreover, the calculation method of maximum identification distance is proposed in passive backscatter RFID systems. The research results show that antenna parameters directly affect identification distance. Furthermore, these influencing factors, such as antenna gain, operational frequency, radar cross-section, quality factor, polarization mode, and the application environment etc, play an important role for identification distance in passive backscatter RFID systems. The results are useful for optimizing the performance of passive backscatter RFID systems and antenna design.

Key words: Radio Frequency Identification（RFID）, identification distance, antenna, performance parameter

摘要： 针对RFID技术应用的日益重要性，基于电磁场散射和微带天线理论，系统地研究了无源反向散射RFID系统识别距离的影响因数，并提出了无源反向散射RFID系统最大识别距离的计算方法。研究结果表明，天线参数直接影响系统的识别距离，其中，天线的增益、工作频率、雷达截面、品质因数、极化方式和应用环境等参数起决定性作用。研究结果对优化无源反向散射RFID系统的性能及天线设计有益。

关键词: 射频识别, 识别距离, 天线, 性能参数