| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground plane antenna having a directive characteristic with less variations over a wide angle in a region close to the direction of the extension of a monopole element at a low cost. SOLUTION: The ground plane antenna is provided with: a ground plane made of a conductor; the monopole element installed in the middle of the ground plane; and a directivity adjustment plate made of a conductor and placed to cover the monopole element. The directivity adjustment plate is disposed in parallel with the ground plane, and the gap (D) between the ground plane and the directivity adjustment plate satisfies a relation of D≤0.5λp, whereλp is a free space wavelength with respect to an operating center frequency fp. The directivity adjustment plate is a disk the radius (Rpap) of which satisfies a relation of 0.70λp≤Rpap≤0.95λp, and the ground plane is a disk whose radius (Rgp) satisfies a relation of Rgp≥1.7λp. COPYRIGHT: (C)2004,JPO
|
