| 摘要 |
The invention relates to a multiband antenna structure suitable for mobile stations in particular. The radiating elements of the antenna include not only a helix (210) but also the joining piece (220) that attaches the helix to the apparatus. The helix is shaped such that the distance between its conductor turns varies. The electrical length of the joining piece is increased e.g. by means of a conductive projection (226) that remains within the covering of the apparatus. By suitably dimensioning the parts, at least five of the resonances that the helix and joining piece have together and separately are arranged at useful points on the frequency scale. The structure according to the invention is despite the several bands simple and relatively low in production costs.
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