用于超高频射频识别读写器Mixer-First接收机的新型直流分量消除技术  

A New DC Cancellation Technique for a Mixer-First Receiver in UHF RFID Reader

作　　者：郑凡凡[1] 谈熙[1] 闵昊[1] ZHENG Fanfan TAN Xi MIN Hao(State Key Laboratory of ASIC ＆ Systems, Fudan University, Shanghai 201203, China)

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室,上海201203

出　　处：《复旦学报（自然科学版）》2017年第4期495-502,共8页Journal of Fudan University：Natural Science

摘　　要：由于收发隔离度有限,超高频射频识别读写器的接收机面临着发射机载波泄漏的问题,基于MixerFirst结构的接收机,提出了一种新型的直流分量消除技术.在无源混频器的中频输出端设计一个由电感、电容等器件组成的带通滤波器,滤除泄漏载波经过下变频产生的直流分量.同时相比于传统的交流耦合方式,该技术可以缩短直流分量的稳定时间.仿真结果表明,当标签返回信号数据率为400kb/s时,该结构的带通滤波器的直流衰减约为-50dB,同时直流分量的稳定时间约为6μs,只有传统交流耦合方式的一半左右.该技术可以扩展接收机的动态范围.The receiver in ultra-high-frequency（UHF）radio frequency identification（RFID）reader suffers from large carrier leakage due to finite TX-to-RX isolation.A new DC cancellation technique for a Mixer-First receiver is proposed in this paper.A bandpass filter composed of an inductor and a capacitor is designed to cancel the large DC component caused by the carrier leakage at the output of the passive mixer.Compared with the conventional AC coupling,the new technique is able to shorten the settling time of the DC component.Simulation results indicate that the attenuation to the DC component is around-50 dB when the data rate of the back-scattered FM0 signal is400kb/s.The settling time is around 6μs and half of that of the conventional AC coupling.The proposed technique can extend the dynamic range of the receiver.

关 键 词：射频识别读写器 接收机 载波泄漏 直流分量消除 带通滤波器 

分 类 号：TN432[电子电信—微电子学与固体电子学]