BUILT-IN ANTENNA OF PORTABLE RADIO APPARATUS

摘要

An object of the invention is that a user obtains high antenna gain with a simple construction in various use conditions of a portable wireless unit. <??>To achieve the above object, in the invention, of a conductive antenna element, a part of a length of a substantially half-wavelength is used as a monopole part (1), and is disposed along the inside of a housing at the upper end of a portable wireless unit. Of the antenna element, the remaining part of a length of a substantially 1/4 wavelength is used for an inverted-F antenna part (2), and disposed parallel to a ground plate surface within the housing of the portable wireless unit. The inverted-F antenna part (2) is disposed parallel to the upper end of the portable wireless unit (6). One end of the inverted-F antenna part (2) is connected to the ground plate (5) through an earthing point (3) provided at one end. A feeding point (4) is provided spaced from the earthing point by a predetermined distance. With such an arrangement, there is no need of using an impedance matching circuit. The construction of the portable wireless unit is simplified. High antenna gain is secured under various use conditions. <IMAGE>