A broadband patch antenna including a planar metallic patch sheet that is provided with right-angled edges and is disposed at a predetermined first height above and parallel to the planar base area of an electrically conducting reflector, and a device for feeding an RF signal into the metallic patch sheet. Further, the light-emitting device manufactured according to the method and the lighting device including the light-emitting device are provided. In the index building workflow, documents are received and analyzed to extract features from the documents. The indicator lamps are arranged at the first openings.