ANTENNA SYSTEM FOR SEARCHING DIRECTION OF RADIO WAVE WITH RADIO WAVE ABSORBING BODY

摘要

PURPOSE:To prevent an input/output matching characteristic from being deteriorated over a wide frequency band by arranging a radio wave absorbing body at the rear side of the antenna. CONSTITUTION:Plural unidirectional beams are arranged by arranging unidirectional antennas whose unidirectional directivity is formed through the arrangement of a flat or recessed radio wave absorbing body 2 at the rear face of the antenna 1 in a ring or a sector shape. Since the radiation characteristic at the rear face side is erased, the action such as synthesis/ interference with the reflected wave by a reflector and the radiation characteristic of the antenna 1 itself does not exist at all. Thus, the deterioration in the input/output matching characteristic due to the frequency condition/distance between the antenna and reflecting plate is not caused.