| 摘要 |
PURPOSE: To provide a communication method which avoides communication with both antennas adjacent to each other and secures the communication with only one of these two antennas to detect a specific position by limiting intentionally the communication areas of both adjacent antennas. CONSTITUTION: When a mobile object to be detected moves to a place under the arrayed antennas A4, A5 and A6, the specific one of these antennas where the mobile object is positioned is detected. The microwaves are supplied to the antennas A4 to A6 from a transceiver 30 and these radiated microwaves are transmitted to an answer unit 40 of the mobile object as signals. The necessary data are included in the carriers which are included in the unit 40 and therefore received by one of antennas A4 to A6. Then the antenna that received the reflected carriers is detected. The frequencies of the microwaves supplied to the antennas A4 to A6 are set at f4=2.447GHz, f5=2.450GHz and f6=2.453GHz respectively which are shifted by 3MHz from each other. In such a constitution, the mutual overlapping is eliminated among the communication areas 6, 7 and 8. |
