An antenna is provided. The antenna includes a substrate, a ground element, a first feed conductor and a second feed conductor. The substrate includes a first surface and a second surface. The ground element is formed on the first surface, wherein the ground element has an aperture, the aperture is funnel shaped, the aperture has an opening portion and a convergent portion, and the opening portion is connected to the convergent portion. The first feed conductor is disposed on the second surface, wherein the first feed conductor feeds a first signal to the aperture. The second feed conductor is disposed on the second surface, wherein the second feed conductor feeds a second signal to the aperture.