RFID is an ADC technology that uses radio-frequency waves to transfer data between a reader and a movable item to identify, categorize, and track. RFID is fast, reliable, and does not require physical sight or contact between reader/scanner and the tagged item. RF tags, antennas, interrogators, host computers and appropriate software constitute a RFID system.

The following is the sequence of the communication:

• Host Manages Reader(s) and Issues Commands
• Reader and tag communicate via RF signal
• Carrier signal generated by the reader (upon request from the host application)
• Carrier signal sent out through the antennas
• Carrier signal hits tag(s)
• Tag receives and modifies carrier signal
• “sends back” modulated signal (Passive Backscatter - FCC and ITU refer to as “field disturbance device”)
• Antennas receive the modulated signal and send them to the Reader
• Reader decodes the data
• Results returned to the host application