PURPOSE: To realize the microwave antenna able to receive a circularly polarized radio wave with a high gain.
CONSTITUTION: A front plate member 1 and a depth plate member 2 made of a conductive material respectively are arranged in parallel with an interval. The surrounding of a space between the front plate member 1 and the depth plate member 2 is surrounded by a surrounding member 4 made of a conductive material. Plural reception hole arrays 15a-15d are provided to the front plate member 1, in which lots of plural reception holes 16a-16d to introduce a circularly polarized radio wave incoming from the front side of the front plate member 1 into the said space are arranged in a ring shape, and a feed hole 23 to introduce the radio wave is provided in the middle of the depth plate member 2.
SUGIURA TOSHIHIRO
HONMA SEIICHI
