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(11) | EP 0 736 925 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A double-acting antenna and a mobile phone comprising such an antenna |
| (57) The invention relates to a double-acting antenna of a radio communication device,
whereby the antenna can be pushed partly inside the cover (4) of the radio communication
device and whereby it function as an antenna both in the extracted or active position
(Fig.3a) and in the retracted or passive position (Fig.3b). In the passive position
that section (2) of the antenna which is pushed inside the cover (4) of the radio
communication device functions as a part of the matching circuit (19), which adapts
the impedance of the section left outside so that it corresponds to the impedance
of the antenna port (11) of the radio communication device. For this purpose the arrangement
comprises connecting means (10) to connect one end of the retracted section (2) to
the ground potential the electrical length of the retracted section (2) is substantially
shorter than a quarter of the used wave-length. |