An antenna of a radio apparatus, the directional pattern of which can be altered
controllably. The antenna comprises at least one conductive element, additional
from the viewpoint of the basic operation of the antenna, for shaping the directional
pattern of the antenna. Such a conductive element (330, 340) is connected
to signal ground at a ground point relatively near the feed point (F) of the antenna.
The conductive element has a part (331) the length of which is about a quarter
of the wavelength at an operating frequency of the antenna, pointing from the ground
point (G) in a direction substantially opposite to the feeding direction of the
radiating element (320). That part is used to equalize the directional pattern
of the antenna in the receiving band. In addition, the conductive element has a
second part (332) pointing from the ground point to the feeding direction
of the radiating element to set a directional pattern notch at transmitting band
frequencies in a desired direction.