The RFID technology includes two parts for example the tag and the reader. Two parts are there in the reader such as an antenna and the transceiver. A weak radio signal is formed with the transceiver. The range of this signal may vary from some feet to yards.
This signal is important for activating the tag and the antenna is used to transmit the signal. A variety of transponder tag is available in several packages. You may search for the RFID chip timing Chattanooga Tennessee on the Internet to obtain more valuable information on this regard.