RFID reader is also known as interrogator. It is used to read data from RFID tag.
The reader has an antenna that emits radio waves; the tag responds by sending back its data.
A number of factors can affect the distance at which a tag can be read (the read range). The frequency used for identification, the antenna gain, the orientation and polarization of the reader antenna and the transponder antenna, as well as the placement of the tag on the object to be identified will all have an impact on the RFID system’s read range.
Three major RFID manufacturers available for choice in the market: ThingMagic, Symbol, and Alien.