| 摘要 |
A double-action antenna structure includes, e.g. a PIFA-type antenna inside the casing of a mobile station, a coupling element and a moveable whip element. The coupling element is a relatively small conductive element between the radiating plane and ground plane of the PIFA, galvanically isolated from the radiating plane and ground plane. When the whip element is retracted, it has no significant coupling to the PIFA parts. When the whip element is extended, its lower end is galvanically connected to the coupling element so that a significant electromagnetic coupling is established between the whip element and the radiating plane of the PIFA. Thus the whip element is fed through the PIFA without being in galvanic contact with it. The coupling element further provides for the matching of the whip element. The internal and external antennas may be designed and optimized relatively independently of each other.
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