| 摘要 |
PROBLEM TO BE SOLVED: To provide a sector antenna at a low cost that has a simple two-dimensional structure, can be made small in size and easily worked with high accuracy. SOLUTION: This sector antenna 1 has directive antennas 10, 20-60 placed in radial directions R1, R2 to R6 separated by 60-degree from each other around a center O of a dielectric base. This directivity antenna has a plurality of antenna elements 11, 12 to 63 orthogonal in the radial direction and placed in a form of an array at an equal interval and a selection exciting means (microstrip line and sector switch) that selects any one of a plurality of the directivity antennas and excites the selected antenna so that its beam direction is directed to the center O. The antenna elements can be produced with high accuracy through the printed circuit board technology, even when they are excited, there is no obstacle to make its antenna characteristics deteriorate, in the beam direction and attain backward excitation to miniaturize its structure. Since the feeding start position is set to the center through the backward excitation, the wiring can be simplified.
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