| 摘要 |
PURPOSE:To eliminate influences of reflected waves from th radome, by inserting a resistance board which absorbs the mode perpendicular to the basic mode of a horn antenna, into the horn antenna near the radome. CONSTITUTION:A horn antenna 1 has an opening 5 which is facing to a radome 3. The opening 5 is formed by a flare 4. In said antenna 1, a resistance board 6 is installed to a location where the electric field component of the mode perpendicular to the basic mode of an electric power feeding section 2 becomes the maximum, that is to say, at the center of the shorter side of a rectangle formed by the horn antenna 1 and the feeding section 2 and in parallel to the longer side. Said resistace board 6 has a tapered section as shown in the dia- gram in the flare section 4. A part of the radiated electric power from the horn antenna 1 is reflected by the radome 3 and returns to the antenna 1 as a polarized wave which is perpendicular to the radiated polarized wave. The reflected wave is absorbed by the resistance board 6 and, therefore, the radiation characteristics of the horn antenna 1 will not be disturbed. |
