An RFID system consists of a transponder integrated or attached to an object or living being and a reader capable of receiving the transponder signature.
The reader contains software (microprogramme) which steers the real reading process and a RFID-Middleware with interfaces to other EDP systems and data banks.
Normally the reader generates an electromagnetic high-frequency field of low reach, mainly with induction coils. This field does not only transfer data, but supplies the energy necessary for the transponder. Only if bigger reach should be achieved and the costs of the transponders are not very critical, active transponders with own electricity supply are used. Mostly the frequency 13.56 MHz is used, which is also the frequency to which RFID warning devices react.
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How does RFID function, actually?
The different transponders RFID kinds
The practical application of RFID