ANTENNA UNIT FOR PORTABLE PHONES

摘要

An antenna unit for portable phones comprising: a first cylinder (4) erecting vertically from the upper part of a case (1) of a portable phone; a four-element dipole array antenna (4a-4d) connected to a transmitter/receiver circuit incorporated in the case through a feeder, the antenna elements being arranged on the surface of the first cylinder at regular intervals at a tilt angle to the center axis of the cylinder and having a length of about one half of the wavelength; a second cylinder (5) having an outer diameter smaller than the inner diameter of the first cylinder and retractable into the first cylinder, the second cylinder being adapted to erect vertically coaxially above and near the first cylinder when it is drawn out of the first cylinder; and four linear conductors (5a-5d) arranged on the surface of the second cylinder at regular intervals at a tilt angle to the center axis of the cylinder. This antenna unit has a good gain and circular polarization characteristics in a wide coverage and an excellent portability because of the telescopic construction.