Dual antenna

Abstract

A dielectric dual antenna (300) with a dual-band operation for small-sized radio apparatuses comprises one partial antenna (310) to implement the lower operating band of the antenna and the other partial antenna (320) to implement the upper operating band. The partial antennas have a shared feed point (FP) in the antenna structure, e.g., at the end of a radiating element (312) of one partial antenna, in which case the other partial antenna receives its feed galvanically through said radiating element by a short intermediate conductor (332). The partial antennas are located so that their substrates (311, 321 ) are heads face to face, and the main directions of the radiating elements, i.e., the conductive coatings of the substrates, starting from the shared feed point are opposing. The tunings of the partial antennas corresponding to different operating bands are obtained independent from each other without discrete matching components.

Description

technical field [0001] The present invention relates to an antenna structure for radio equipment of small size, the structure comprising two electrically relatively separate parts. Background technique [0002] In small-sized portable radio devices such as mobile phones, the antenna is preferably placed inside the device housing for ease of use. Furthermore, when trying to make the antenna take up as little space as possible, its design becomes very demanding. Additional design difficulties arise if the radio has to operate in several frequency ranges, the more difficult the wider these frequency ranges are. [0003] Internal antennas are mostly planar in structure, whereby they have a radiation plane and a ground plane at a certain distance therefrom. Planar antennas can be made smaller by fabricating the radiating plane on the surface of a dielectric substrate, rather than making the radiating plane air-insulated. Naturally, the higher the dielectric constant of the mat...

AI Technical Summary

Problems solved by technology

[0007] The disadvantage of the solution according to Fig. 2 and other similar arrangements is the space required for matching components on the circuit board and the additional cost of manufacturing these components

It is conceivable that the required matching could be done with wire patterns on the surface of the board without the need for separate parts, but all these patterns would require a relatively large area on the board anyway

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