Patent ID: 8188934

Claim:
An antenna for a radio device, comprising a feed tower and a first radiator, at a first end of the feed tower wherein the first radiator is a folded dipole made from metal strips connected with each other on at least two surfaces of a dielectric support plate, which plate is mechanically attached to the first end of the feed tower; the feed tower comprises a conductive first branch connected to a first point in the first radiator and a conductive second branch connected to a second point in the first radiator, which branches are in a conductive connection with each other at a second end of the feed tower; the feed tower further comprises a first feed conductor, a first portion of which forms a transmission line with said first branch and a second portion of which extends from said transmission line to the second branch at the first end of the feed tower, in said second point; inside the first branch there is a cavity extending from the first end of the feed tower to the second end; said transmission line comprises an electrically conductive wall of said cavity and of a portion of the first feed conductor, which travels in said cavity; there is a hole in the wall of the cavity at the first end of the feed tower on the side of the first branch facing towards the second branch; and the first feed conductor travels through the hole.