Although the history of RFID can be traced to the 1930s, the technology underlying RFID finds its roots back in 1897, when Guglielmo Marconi invented the radio. RFID applies the same principles of physics as those used in radio broadcasting, where radio waves, a form of electromagnetic energy, transmit and receive various types of data.
To better understand this similarity, visualize a radio station broadcasting voice or music through a transmitter. This is essentially data encoded into radio waves of a specific frequency. In a separate location, the listener has a radio that can be tuned to decode the data (voice or music) being transmitted by the radio station. Almost everyone has experienced the changes in quality of radio reception when traveling by car. The further you get from the transmitter, the weaker the signal becomes. The distance in all directions, or area, that a radio transmission can cover is determined by environmental conditions and the size and power of the antennae on each side of the communication link. Using RFID terminology, the radio station transmitter functions like a tag, also known as the transponder (derived from the terms transmitter and responder), while the radio is the reader, also known as the interrogator. The antennae determine the reach, also known as the range.
These three componentsthe transponder or the tag, the receiver or the reader, and the antennaeare the building blocks of all RFID systems. Variations in power, size, antenna design, operating frequency, data capacity, and software to manage and interpret the data create a myriad of possible applications where RFID technology can be used to solve real-world business problems.