A radio frequency identification (RFID) reader includes a plurality of signal antennas, which are respectively arranged in directions that are not parallel to and co-linear with each other. Each of the signal antennas has a predetermined antenna field pattern and operates with a predetermined carrier wave frequency. A wireless receiver is connected to the signal antennas. A signal conversion unit is connected to the wireless receiver. A frequency generator generates the carrier wave frequency to the signal antenna. A microprocessor is connected to the signal conversion unit and the frequency generator.