A broadband antenna includes a substrate; a grounding unit; a first radiating element, including a first segment and a second segment substantially perpendicular to each other, wherein the first segment is electrically connected to the grounding unit and the second segment extends toward a direction; a second radiating element, coupled to the first radiating element; a third radiating element having a terminal coupled to or electrically connected to the second radiating element and another terminal electrically connected to the grounding unit; and a signal feed-in element electrically connected to the third radiating element for transmitting or receiving a radio signal; where the first, the second and the third radiating elements are disposed on the substrate along the direction defined by an order of the first segment of the first radiating element, the second radiating element and the third radiating element.