Patent ID: 7501983

Claim:
A planar antenna structure for a radio device having at least one operating band comprising: a ground plane; a radiating element galvanically isolated from the ground plane and other conductive parts of the radio device; a feed element having an antenna feed point, wherein the feed element is only electromagnetically coupled to the radiating element so as to transfer energy to the radiating element and receive energy from the radiating element; a feed circuit that couples the antenna feed point to an antenna port of the radio device, wherein the feed circuit includes a reactive component and also couples the antenna feed point to the ground plane; the feed circuit including a feed circuit board between the feed element and the ground plane, the feed circuit board including a feed conductor which galvanically connects said feed point to the antenna port; wherein the feed conductor and the ground conductor are meandering strip conductors, which have certain inductances which act as the reactive component, and a ground conductor which electromagnetically connects the feed conductor to the ground plane at a point along the feed conductor; whereby said at least one operating band is set to a desired range on the frequency axis so as to match the antenna.