Backscatter-passive RFID tag is detected without power supply
Generally , three main parts make up in a passive RFID system – an RFID reader , an RFID antenna, and RFID tags. Unlike active RFID tags, passive RFID tags only have two main components – the tag’s antenna and the microchip or integrated circuit (IC).
As the name implies, passive tags wait for a signal from an RFID reader. The reader sends energy to an antenna which converts that energy into an RF wave that is sent into the read zone. Once the tag is read within the read zone, the RFID tag’s internal antenna draws in energy from the RF waves. The energy moves from the tag’s antenna to the IC and powers the chip which generates a signal back to the RF system. This is called backscatter. The backscatter, or change in the electromagnetic or RF wave, is detected by the reader (via the antenna), which interprets the information.