PURPOSE: To reduce the side lobe of an antenna radiation pattern by sticking a radio wave absorbing body having a prescribed width to a part or the whole of the outside circumference of a main reflective mirror.
CONSTITUTION: An antenna device consists of a feeding horn 1, plural auxiliary reflective mirrors 2 and 3 consisting of rotating quadratic surface reflectors, and a main reflective mirror consisting of a rotating parabolic reflector, and radio waves emitted from a focus F1 of the auxiliary reflective mirror 2 are converged at a focus F2 common to the auxiliary reflective mirror 3 and the main reflective mirror 4 and are converted to plane waves by the main reflective mirror 4 and are radiated toward the front of the antenna. A radio wave absorbing body 5 is stuck to the whoel of the outside circumference of the main reflective mir- ror 4 to reduce the electric field level around the main reflective mirror 4, thus reducing the radiation level of unnecessary radiation waves due to diffracted waves.
SEGAWA JIYUN
FURUNO TAKAMASA
ABE KOUJI
MITSUBISHI ELECTRIC CORP