提出了一种全新的射频识别(RFID)数字接收机的实现方案。针对RFID系统实时性的要求,该设计采用简化的相关算法取代数字锁相环结构,快速准确地捕获频率范围在31.2kHz-780.8kHz内的突发信号,并实现接收数据解码。与采用过零检测方案的数字接收机相比,本设计具有更强的抗干扰能力。该数字接收机在Altera Stratix II EP2S60上验证通过,取得了良好的性能。
A direct conversion receiver with optimized tolerance to local carrier interference is designed and implemented in a 0.18μm 1P6M mixed-signal CMOS process for a 900MHz RFID reader transceiver. A baseband amplifier with series feedback topology is proposed to achieve passive mixer buffering,baseband DC cancellation,and signal amplification simultaneously. The receiver has a measured input ldB compression point of - 4dBm and a sensitivity of - 70dBm when 10dB SNR for digital demodulation is required. The receiver is integrated in a reader transceiver chip and consumes 90mA from a 1.8V supply.
