A Mixed-Signal Architecture of Channel Select Filtering with Oversampled ADC for Multi-Standard RFID Reader Receiver

Radio frequency identification (RFID) technology is popular nowadays. One key challenge for RFID reader design is to receive the tag´s weak signal in the presence of large interference signal from other readers on adjacent channels. In this paper, a highly reconfigurable mixed-signal architecture for channel select filtering with the help of oversampled delta-sigma modulator is proposed. It allows the reader to support multi-standard operating environment with less power consumption and silicon area for single-chip implementation compared with pure analog or digital channel select filtering approach. The challenge of the interference to the system is discussed. Detail descriptions of the architecture and some performance analysis are presented.