PURPOSE: To improve the wide-angle directional characteristics, by securing a use of the surface which blocks the electric wave sent from the main reflector of the pole supporting the secondary reflector for the part of the rotational paraboloid centering on the electric wave axis.

CONSTITUTION: The part of the electric wave sent from the primary horn 5 is blocked by the secondary reflector pole 3 when it is radiated into the air from the main reflector 1 via the secondary reflector 2. And the electric waves concentrate under the focus of the paraboloid formed by the pole after being reflected by the pole. Here the electric wave absorber 7 is provided, and thus the electric wave blocked by the pole can be absorbed without being scattered into the air.