| 摘要 |
PROBLEM TO BE SOLVED: To provide a slot antenna device for circularly polarized wave which can be easily miniaturized and manufactured at a low cost. SOLUTION: The slot antenna device 10 is provided with a circuit board 12 on which a high-frequency circuit 11 is disposed, and a shield case 13 for housing the circuit board 12. A cross slot 14 and a feeding pin 15 are formed on the top surface plate 13a of the shield case 13. The cross slot 14 is opened into a shape in which a first slot 14a and a second slot 14b having a different longitudinal length at a predetermined amount cross each other at right angles, and the shortest distances from the feeding pin 15 to each of the slots 14a, 14b are almost the same. When the top surface plate 13a is fed with power via the feeding pin 15, the slots 14a, 14b are each excited and linearly polarized waves perpendicularly to each other are radiated. However, since resonant mode of each of the slots 14a, 14b has a phase difference of about 90°, the antennas operate as a circularly polarized antenna. COPYRIGHT: (C)2005,JPO&NCIPI
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