Patent ID: 7847737

Claim:
An antenna apparatus comprising: a patch antenna unit in which a radiation conductor and a ground conductor plate are arranged so as to face each other with an insulating material disposed therebetween, a power-feed point is provided at a position slightly offset from the center of the radiation conductor, and a high-frequency electric field is supplied between the radiation conductor and the ground conductor plate; a first surface-wave propagation suppression area in which a surface-wave propagation suppression mechanism for suppressing surface-wave propagation is mounted in a first outer surrounding area of the ground conductor plate in the offset direction of the power-feed point; a second surface-wave propagation suppression area in which a second wave propagation suppression mechanism for suppressing surface-wave propagation is mounted in a second outer surrounding area of the ground conductor plate in a direction opposite the offset direction of the power-feed point; and an insulating area in which an electric-field intensity between the radiation conductor plate and the ground conductor plate is relatively low and the surface-wave propagation suppression mechanism is not arranged.