In a reflector antenna[?], the relative reduction in the effective aperture of the antenna caused by the masking effect of other antenna parts, such as a feed horn or a secondary reflector, which parts obstruct the radiation path.
... Justinian, he was a Christian and possibly bishop of Croton. In approximately 580, he wrote "De origine actibusque Getarum[?]" (The origin and deeds of the Goths), "D ...