An antenna device includes a housing that includes a first section extending along a first direction and a second section extending along a second direction that crosses the first direction, an antenna element that includes a first portion extending along the first direction within the first section of the housing and a second portion extending along the second direction within the second section of the housing, a first conductor on a bottom surface of the antenna element, and a second conductor on a side surface of at least one of the first and second portions.