Introduction to RFID
With RFID (Radio Frequency Identification) the electromagnetic or electrostatic coupling in the RF portion of the electromagnetic spectrum is used to transmit signals.
An RFID system consists of three components: an antenna and transceiver (often combined into one reader) and a transponder (tag). The antenna transmits a signal that activates the transponder. When activated, the tag transmits data back to the antenna. The data is used to notify a programmable logic controller that an action should occur.
Several frequencies have been allocated for RFID purpose: from low frequencies up to microwaves.
