An antenna assembly in a vehicle is provided. The antenna assembly includes a first plane including a first edge and a second edge extending in parallel to each other in a first direction, a second plane spaced apart from the first plane that overlaps the first plane and including a third edge extending along the first edge, and a fourth edge extending along the second edge, a non-conductive layer interposed between the first plane and the second plane, and a plurality of wireless communication circuits electrically connected to the antenna assembly, wherein the first conductive pattern and the second conductive pattern are positioned diagonally at opposing corners with each other when viewed from above the first plane, and wherein the third conductive pattern and the fourth conductive pattern are positioned diagonally against each other without overlapping with the first and second conductive patterns, when viewed from above the first plane.