| 摘要 |
A retractable/extendable antenna (1) for portable radio device is provided, which expands the bandwidth for the operating frequency of 1.5GHz. This antenna comprises (a) a casing (20); (b) a first linear antenna element attached retractably or extendably to the casing (20); the first element (whip element 6) being located outside the casing and fed with electric power to be active in the extended state while located inside the casing (20) and fed with no electric power to be inactive in the retracted state; and (c) a second linear antenna element (3) shorter than the first element (6), which is connected mechanically to one end (5) of the first element (6) and disconnected electrically therefrom; the second element (3) being located outside the casing (20) and fed with no electric power to be inactive in the extended state while located outside the casing (20) and fed with electric power to be active in the retracted state. The first and second elements (36,33) may be electrically connected to each other (Fig.16a,16b).
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