PURPOSE: To obtain an antenna having a wide azimuth valid range and an asymmetrical elevation valid range by providing two conical parts attached to a grounded back plate whose tapered end parts are faced with each other. CONSTITUTION: Two conical parts in an unequal size have curved end parts, and a power is supplied through a rectangular waveguide passing through a back plate to this antenna. That is, a conical upper part 12 and a conical lower part 14 are attached to a grounded back plate 10. Then, a rectangular waveguide 16 passes through the back plate 10 between the tapered end parts of the conical upper part 12 and the conical lower part 14. Also, the waveguide 16 ends in the neighborhood of the face of the back plate 10, and a vertical wall body is extended beyond the face of the back plate 10 so that projecting parts 20A and 20B can be formed. Thus, an antenna whose side rope and ripple in a main beam is low when it is operated with frequencies in a wide range can be obtained.
展开▼
