Antenna apparatus
An antenna apparatus includes 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 surface-wave propagation suppression area in which a surface-wave propagation suppression mechanism for suppressing surface-wave propagation is mounted in an outer surrounding area in the offset direction of the power-feed point in which an electric-field intensity is generally maximum within the end portion of the radiation conductor plate; 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.
1. 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.
2. The antenna apparatus according to claim 1 , wherein, in each of the surface-wave propagation suppression areas, a plurality of thumbtack-type artificial magnetic conductor elements, in each of which a plate-shaped conductor is supported by a post-shaped conductor, are arranged.
3. The antenna apparatus according to claim 1 , wherein, in each of the surface-wave propagation suppression areas, an artificial magnetic conductor element, in which texture is applied to a plate-shaped conductor, is arranged.