Patent ID: 8169363

Claim:
An antenna device comprising: an antenna substrate having subarray antennas, arranged parallel to each other with an interval, the interval being less or equal than a free-space wavelength, each subarray antenna including antenna elements and first feed lines, the first feed lines feeding signals to the antenna elements, feeding interfaces, each feeding the signals to each of the first feed lines a back surface of the antenna substrate having the feeding interfaces; and a feed line substrate attached along the back surface, the feed line substrate including second feed lines, each having one end portion and other end portion, the other end portion having wider width than the one end portion, the one end portions are arranged in a line to each other with the interval, and the other end portions are alternately arranged across the one end portions, first mode transformers, each being located in the one end portion, each being connected to each of the feeding interfaces, and second mode transformers, each being located in the other end portion.