Internal multiband antenna

摘要

A multiband antenna applicable as an internal antenna in small mobile terminals especially. The antenna (200) is a PIFA placed inside the housing of a mobile station with at least two operating bands. A first resonance falling into a lower operating band is produced by means of a radiating conductive pattern (B21) in planar element (220). To improve the characteristics of the antenna in the upper operating band the planar element further comprises a slot (232) which goes between the feed point (F) and the short-circuit point (S) of the antenna. The radiator provided by this slot can be considered a quarter-wave slot radiator or a half-wave loop radiator. The PIFA further may have another radiator, which resonates in the upper operation band. By means of said slot the upper operating band of an antenna can be widened or the radiation in the horizontal plane in the upper operating band can be made more effective.