Patent ID: 8330665

Claim:
An antenna device for a portable radio communication device adapted for receiving and/or transmitting radio signals in at least a first and a second operating frequency band, the antenna device comprising: a half-loop radiating element including a feeding portion at a first end of the half-loop radiating element, and a grounding portion at a second end of the half-loop radiating element, the half-loop radiating element arranged to operate at FM frequencies; a capacitor at the feeding portion; an inductor at the grounding portion; a first matching network or filter connected to the first end of the half-loop radiating element at the feeding portion, for a FM receiver; and a second matching network or filter connected to the second end of the half-loop radiating element at the grounding portion, for another receiver for frequencies at least ten times higher than FM frequencies; the first matching network or filter is connected to the capacitor in parallel; the second matching network or filter is connected to the inductor in parallel; the half-loop radiating element is arranged to simultaneously with FM frequencies operate at frequencies at least ten times higher than FM frequencies; the capacitor is arranged to short circuit the half-loop radiating element to ground for frequencies at least ten times higher than FM frequencies; and the inductor is arranged to short circuit the half-loop radiating element to ground for FM frequencies.