| 摘要 |
PROBLEM TO BE SOLVED: To improve the accuracy of detecting the bearing of an arriving radio wave.SOLUTION: Each of the power-feeding point of a first antenna element 21a and the power-feeding point of a second antenna element 21b is located nearer to each other than the position of the center of gravity of the shape of the first antenna element 21a and the position of the center of gravity of the shape of the second antenna element 21b. Each of reception units 11 and 12 performs frequency conversion and other processing on the signals received by the first antenna element 21a and the second antenna element 21b, and outputs a frequency signal. An amplitude difference detection unit 13 detects a difference in the amplitudes of the frequency signals outputted by the reception unit 11 and the reception unit 12. A phase difference detection unit 14 detects a difference in the phases of the frequency signals outputted by the reception unit 11 and the reception unit 12. A rough measurement unit 15 specifies, from the amplitude difference, a range in which the bearing of an arriving radio wave can be taken. A bearing detection unit 16 detects angles from the phase difference, and detects from among the detected angles, as the bearing of the arriving radio wave, an angle falling within the range in which the bearing of the arriving radio wave can be taken as specified by the rough measurement unit 15.SELECTED DRAWING: Figure 1 |
