A planar broadband antenna includes a flat elliptical antenna device. The elliptical antenna device includes a central antenna element, a first angular antenna element and a second angular antenna element. The central antenna element is disposed parallel to a support. The angular antenna elements are formed by two opposite segments of the elliptical antenna device and point toward the support. The first angular antenna element is provided with a base point through which a signal is capable of being fed in. An impedance device connects the second angular antenna element to a ground point located near the base point.