Impedance matching means between antenna and transmission line

An impedance matching means according to the present invention is used with an antenna and is realized by a parasitic element for tuning an impedance of the antenna. The antenna comprises a grounding plate, an radiating body arranged on the grounding plate and a transmission line coupled to said radiating body and grounding plate. The parasitic element formed of a narrow metal sheet and configured as a bridge shape is arranged on the grounding plate. The parasitic element has a first and a second ends, both of which are electrically connected to the grounding plate. The arrangement of the parasitic element results in a change of the impedance of the antenna, so the impedance matching between the antenna and the transmission line can be achieved.