Patent ID: 7898490

Claim:
A primary radiator comprising: a plurality of horns each having an opening on a larger-diameter side and an opening on a tapered smaller-diameter side opposite to the larger-diameter side; at least one corrugated portion provided around each of said opening on the larger-diameter side of said horns; said at least one corrugated portion including an outermost corrugated portion being formed to surround all of said plurality of horns and including an innermost corrugated portion being formed to surround one of said plurality of horns, and said outermost corrugated portion being formed of one sheet metal member; a base plate to which said horns and said at least one corrugated portion are fixed; said at least one corrugated portion includes a plurality of corrugated portions including the innermost corrugated portion; a plurality of holes are made in said base plate, respective ends on said smaller-diameter side of said horns are passed respectively through said plurality of holes, and respective peripheries of respective openings on said larger-diameter side of said horns are fixed to respective rims of said holes; and said innermost corrugated portion is fixed to said base plate or to a receiving piece extending from each of said horns such that said innermost corrugated portion is placed concentrically with said opening on the larger-diameter side of each of said horns, wherein the one of said plurality of horns is separately provided from the innermost corrugated portion, where the one of said plurality of horns fits into the innermost corrugated portion.