Abstract: A baseband transmitter for UHF (ultra high frequency) RFID (radio frequency identification) reader is proposed, which supports ISO 18000-6B&6C protocol and works at 840-960 MHz. Taking security and compatibility into consideration, 2-bits PIE-kind encoder and PIE encoder are both implemented, the former is 6 times higher security than the later. In SSB modulation, when there is amplitude mismatch of two quadrature signals, it will generate two frequency bands and result in performance lost. For this problem, an amplitude matching module is integrated. A power adjustment module in baseband is also proposed to enhance the signal and get larger input signal for PA to generate larger PA output power. The whole reader chip is implemented in a 0.18μm CMOS process and consumes 209461 gates and 102.609 mW. The baseband transmitter takes up 22% of the total area. This novel architecture doesn’t bring much lost in area and power consumption compared with other existing designs.

Key words: UHF RFID reader, baseband transmitter, encoder, power adjustment

摘要： 设计了一个超高频射频识别读写器的基带发射机, 该读写器基带芯片工作在840~960 MHz频段, 支持ISO 18000-6B&6C 协议。为了增强安全性同时保证与协议的兼容, 采用2-bits类PIE编码和PIE编码方式, 前者相对后者安全性提高了6倍。针对单边带调制中由于两路正交信号幅度不相等而产生的双频带对标签接收信号产生干扰的问题, 在基带发射机中增加了幅度匹配模块, 尽量消除幅度差异。还在基带部分增加了功率放大模块, 使得到达 PA 的输入信号幅度增强, 从而得到更高的输出功率。整个读写器芯片在0.18μm CMOS工艺下, 电路规模为209461个门, 功耗为102.609 mW, 其中发射机部分占面积的22%。与当前的一些设计相比, 该设计并没有带来较大的面积和功耗损失。

关键词: 超高频RFID读写器, 基带发射机, 编码器, 功率调节