Patent ID: 7019709
Filing Date: 2006-03-28
Classification: H01Q

Abstract:
1. An antenna device comprising: a ground plate; a first radiation plate having a diameter, a side length or a diagonal length of about ½ wavelength in electrical length disposed at a distance from the ground plate; and a second radiation plate having a diameter, a side length or a diagonal length of about ½ wavelength in electrical length disposed at a distance from the ground plate, wherein the first radiation plate has a first power feed port and a second power feed port provided thereon, the first and second power feed ports being disposed so that straight lines linking a position of each of the first and second power feed ports and a middle point of the first radiation plate are orthogonal to each other, the second radiation plate has a third power feed port and a fourth power feed port provided thereon, the third and fourth power feed ports being disposed so that straight lines linking a position of each of the third and fourth power feed ports and a middle point of the second radiation plate are orthogonal to each other, and the orthogonal straight lines of the first radiation plate are rotated at an angle of 45 degrees with respect to the orthogonal straight lines of the second radiation plate.