| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an on-board antenna for reducing an area required for placing a plurality of planar antennas while ensuring desired transmission/reception characteristics. <P>SOLUTION: The on-board antenna is configured by being provided with: a first planar antenna 11 using rear glass of a vehicle as a dielectric base and placed on the interior surface of the rear glass; and a second planar antenna 12 placed inside the first planar antenna 11. The first planar antenna 11 is configured by being provided with: first radiation conductors 21 made of a conductive thin film or the like placed on the interior surface of the rear glass; and a first ground conductor 12 surrounding the first radiation conductors 21 in the outside, and a void part 23 comprising a through-hole is provided inside the first radiation conductors 21. The second planar antenna 12 comprising a second radiation conductor 31 and a second ground conductor 23 surrounding the second radiation conductor 31 in the outside is placed on the interior surface exposed at the void part 23 of the first radiation conductors 21. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
