The present invention provides a broadband antenna that is used in wireless communication systems. The broadband antenna includes a closed looped radiating element having a body section and a hollow section formed by closed compassing by the body section; a grounding element; and a connecting element having a first end electrically connected to the closed looped radiating element and a second end electrically connected to the grounding element. The antenna of the present invention can provide a wider frequency bandwidth and better antenna efficiency.