| abstract |
[PROBLEMS] To efficiently send/receive wireless tag information in a short time, even when wireless tag circuit elements are dispersed over a large area. [MEANS FOR SOLVING PROBLEMS] An interrogator (100) is provided with antennas (1A, 1B, 1C, 1D, 1E) for performing non-contact information communication with an IC circuit part (150) of a wireless tag circuit element (To) to be interrogated, a control circuit (4), and a high-frequency circuit (2) provided with a directivity switch control part (211). The control circuit (4) and the directivity switch control part (211) control directivity of the antennas (1A-1E) to be wide when a communication distance is short, and to be narrow when the communication distance is long, depending at least on the information communication distance. |