An antenna system includes at least one antenna array. The antenna array includes a dielectric substrate, a ground plane, a first radiation element, a second radiation element, a third radiation element, a fourth radiation element, a first feeding element, and a second feeding element. The second radiation element is adjacent to the first radiation element. The first radiation element is positioned between the second radiation element and the ground plane. The fourth radiation element is adjacent to the third radiation element. The third radiation element is positioned between the fourth radiation element and the ground plane. The first feeding element is coupled to a first connection point on the first radiation element and a second connection point on the third radiation element. The second feeding element is coupled to a third connection point on the first radiation element and a fourth connection point on the third radiation element.