ANTENNA DEVICE

摘要

Provided is an antenna device capable of reducing the influences of a bias line in a plane antenna. The antenna device comprises a dielectric substrate, an earthing member formed on the back of the dielectric substrate, a first conductor of a rectangular annulus shape formed on the surface of the dielectric substrate, a second conductor of a rectangular shape so formed on the inner side of the first conductor as to form a closed annular slot, a switch so arranged diagonally of the first and second conductors as to joint the first conductor and the second conductor, a bias line wired on the plane common to the first conductor and the second conductor for controlling the switch, and an open leading end stub connected with the bias line and having a length of a quarter of the wavelength. A wider slot than the width of the bias line is formed in the vicinity of the corner of the first conductor of the rectangular shape. The bias line is wired in a bridge girder shape over the first conductor at the portion where the first conductor and the slot cross, and a feeding point is arranged at the center of the second conductor.