Patent ID: 8144071

Claim:
An antenna device for a portable radio communication device operable in at least four different frequency bands, the antenna device comprising: a first electrically conductive radiating element; a second electrically conductive radiating element; a junction point connecting the first and second electrically conductive radiating elements; a first conductor arranged between the junction point and a source of RF signals; a second conductor arranged between the junction point and the source of RF signals, wherein the second conductor has an electric length that is shorter than an electric length of the first conductor; a controllable switch element provided in series with the second conductor, said controllable switch element being controllable by a current flowing through the controllable switch element; a first filter block provided in series with the second conductor, between the first conductor and the second conductor wherein a common junction between the first conductor and the first filter block is connected to the source of RF signal; said first filter block being arranged to block signals with a frequency lower than the at least four different frequency bands; the first conductor and the first radiating element are connected in series and are together arranged to resonate in a first lower frequency band with the controllable switch element opened; the first conductor and the second radiating element are together arranged to resonate in a first higher frequency band with the controllable switch element opened; the second conductor and the first radiating element are connected in series and are together arranged to resonate in a second lower frequency band with the controllable switch element closed, the second lower frequency band being higher than the first lower frequency band; and the second conductor and the second radiating element are together arranged to resonate in a second higher frequency band with the controllable switch element closed, the second higher frequency band being higher than the first higher frequency band.