Patent ID: 7161541

Claim:
A planar antenna, comprising: a ground area; a first plane radiation member opposing the ground area and providing a first resonant frequency, wherein the first plane radiation member comprises a first ground end, a feeding end, and an intermediate portion disposed between the first ground end and the feeding end, the first ground end is connected to the ground area, and the feeding end inputs signals; a second plane radiation member opposing the ground area and comprising a connecting portion and a first free end, wherein the connecting portion is connected to the intermediate portion, the first free end extends to one side of the first plane radiation member and is separated from the first ground end and feeding end by a first gap, and the feeding end, intermediate portion, connecting portion and first free end constitute a radiation path providing a second resonant frequency; and a third plane radiation member opposing the ground area and providing a third resonant frequency differing from the first and second resonant frequencies, wherein the third plane radiation member comprises a second ground end and a third free end, the second ground end is connected to the ground area, and the third free end surrounds the first and second plane radiation members and is separated from the first and second plane radiation members by a third gap.