Antenna device, wireless terminal, and wireless module

An antenna device comprising:

• a substrate ground having a planar surface;
• a planar radiation element disposed in parallel and opposite to a planar portion of the substrate ground;
• a power feeding point connected to the planar radiation element;
• and
• a ground portion forming a stacked body in which, on a radiation surface side corresponding to a surface of the planar radiation element that is not opposite to the substrate ground, ground patterns made of a conductive material are stacked from the radiation surface in a radiation direction perpendicular to the radiation surface,
• wherein when the radiation direction is assumed to be an upward direction, a respective ground pattern in each layer of the stacked body being formed inwardly of a first portion immediately overlying the ground pattern in another layer located on the radiation surface side, wherein non-ground portions in which the conductive material is not disposed being formed in a second portion immediately overlying the radiation surface, and wherein the non-ground portions in respective layers are formed to be gradually enlarged in the radiation direction.