MULTI-BAND ANTENNA DEVICE AND PORTABLE RADIO COMMUNICATION DEVICE COMPRISING SUCH AN ANTENNA DEVICE

摘要

A multi-band antenna device (10) for a portable radio communication device comprises a parasitic element (14) and a radiating element (12) including a feeding section (16), a length varying section (18) and first and second dual band sections (20, 22). The feeding section (16) stretches along the parasitic element (12). The length varying section (18) is further distanced from the parasitic element (14) than the feeding section (16) and includes a first and a second parallel branch (24, 26) as well as a switch (SW) The first branch (24) is shorter than the second branch (26) for providing resonance in a first frequency band while the second branch provides resonance in a second frequency band. The first and second dual-band sections (20, 22) together provide resonance in a third frequency band.