MOBILE TELEPHONE IDENTIFICATION DEVICE

PROBLEM TO BE SOLVED: To provide a mobile telephone identification device that can configure a transmission reception input output section, without using a circulator for enhancing the performance of a transmission reception and reduce the cost. SOLUTION: Parallel arrangement of 1st and 2nd monopole antennas 33, 34 having a length of λ/4 at an interval of λ/4 or below configures an interrogator antenna 32, which is connected to a transmission output terminal 31 and a reception input terminal 35, that are placed to have directionality of 180 deg.. A microwave signal, outputted from a modulation/transmission section 11, is fed to the transmission output terminal 31 and emitted from the 1st monopole antenna 33, the 2nd monopole antenna 34 receives the part of the microwave signal, which is inputted to a receiving/demodulation section 12. When a wireless tag 20 enters an identification enable area in this state, since the 2nd monopole antenna 34 receives the signal from the 1st monopole antenna 33 and the signal re-emitted from a tag antenna 21 is added, the sum of the received signals is demodulated, and the presence of the wireless tag 20 is recognized.