A broadband antenna includes a substrate, a radiator element disposed on a first surface of the substrate, a grounding element, a conductor element, a conductor arm, and a conductor piece disposed on a second surface of the substrate. The conductor element is provided with a feed point. The conductor element interconnects the radiator element and the grounding element and includes a first conductor section, a second conductor section, and a third conductor section interconnecting the first conductor section and the second conductor section. The third conductor section includes a first part, and a second part connected between the first part and the second conductor section. The first conductor section configures the radiator element into a first radiator portion and a second radiator portion. The conductor piece is conductively coupled to the radiator element and overlaps with projections of the first radiator portion, the first conductor section, the first part, and the conductor arm onto the second surface.