Patent ID: 7538739

Claim:
A flat antenna, comprising: a substrate having a first surface and a second surface opposite to each other; a first antenna module having a first grounding unit, a first radiating unit, a first feeding unit and a second radiating unit, wherein the first grounding unit is disposed on the first surface of the substrate, the first radiating unit has a first opening and is disposed on the first surface of the substrate, the first radiating unit is electrically connected with the first grounding unit, the first feeding unit is disposed on the second surface of the substrate, the second radiating unit has a second opening disposed opposite to the first opening and is disposed on the second surface of the substrate, and the second radiating unit is electrically connected with the first feeding unit; and a second antenna module disposed abreast with the first antenna module and having a second grounding unit, a third radiating unit, a second feeding unit and a fourth radiating unit, wherein the second grounding unit is disposed on the first surface of the substrate, the third radiating unit has a third opening and is disposed on the first surface of the substrate, the third radiating unit is electrically connected with the second grounding unit, the second feeding unit is disposed on the second surface of the substrate, the fourth radiating unit has a fourth opening disposed opposite to the third opening and is disposed on the second surface of the substrate, and the fourth radiating unit is electrically connected with the second feeding unit.