RFD的基本通信原理-3 Far-Field Propagation and Backscatter Principle For successful reading of a passive tag with the backscatter scheme, there are two thresholds to meet the physical requirements.The first is the tag power (sensitivity)threshold,Pts.It is the minimum received power necessary to turn on an RFID chip.The second is the reader sensitivity threshold,Prs.It is the minimum level of the tag signal that the reader can detect and resolve. Distance r Matching Network Reader Za 9 Prs Pt灯 TAG P4 Reader antenna Tag antenna gain Gt gain Gr Fig.1.Far-Field Propagation for RFID systemRFID的基本通信原理-3 • Far-Field Propagation and Backscatter Principle – For successful reading of a passive tag with the backscatter scheme, there are two thresholds to meet the physical requirements. The first is the tag power (sensitivity) threshold, Pts. It is the minimum received power necessary to turn on an RFID chip. The second is the reader sensitivity threshold, Prs. It is the minimum level of the tag signal that the reader can detect and resolve. Pts Prs