Patent ID: 7075486

Claim:
A circularly polarized wave antenna is comprised of: a radiating conductor plate made of a metal sheet which has an outer appearance of a substantially regular polygonal or circular shape and is arranged on a ground conductor with a predetermined distance therefrom; a feed pin extending from a feeding point of the radiating conductor plate and connected to a feeding circuit; and leg pieces extending from four points of the radiating conductor plate for supporting the radiating conductor plate in a state insulated from the ground conductor, wherein the four leg pieces including first, second, third, and fourth leg pieces, the first and second leg pieces closer to each other than to either the third or fourth leg pieces, and the third and fourth leg pieces closer to each other than to either the first or second leg pieces, and wherein, the first and second leg pieces are arranged substantially in line symmetry with respect to one straight line of two straight lines passing through the center of the radiating conductor plate orthogonal to each other, and the third and fourth leg pieces are arranged substantially in line symmetry with respect to the one straight line, the first and third leg pieces are arranged substantially in line symmetry with respect to the other straight line, and the second and fourth leg pieces are arranged substantially in line symmetry with respect to the other straight line, and a straight line connecting the feeding point and the center of the radiating conductor plate forms an angle of about 45 degrees with respect to both of the two straight lines.