| 摘要 |
PURPOSE:To vary the phase of the radiation electric field of a primary feed part so as to correspond to a variation of a wave angle, and to increase a detection probability of a low wave angle area by improvement of the primary feed part, by setting the relative phase of a secondary pattern by the upper part of a reflector, and a secondary pattern by the lower part, to a suitable value. CONSTITUTION:To a reflector 3 of a dual beam system radar antenna are placed a low beam feed part 1 and a high beam feed part 2 on its upper and lower parts, respectively. A primary feed part to the reflector 3 of said constitution is constituted of horn antennas 12, 13, these antennas 12, 13 are placed in parallel on the upper and lower parts, and the ratio of electric power to be fed to these antennas 12, 13 is varied by an electric power distributor 14, and is made in phase. In accordance with a wave angle theta whose right angle has been made ''0'' to the opening of the antennas 12, 13, the ratio of electric power to be fed to the antenna 12 or 13 is varied by the distributor 14, phase of the radiation electric field of the primary feed part is varied in accordance with a variation of the wave angle theta, and a covered area in the angle area of the low wave angle theta is expanded. |
