DUAL BAND ANTENNA WITH A DOME-SHAPED RADIATOR

摘要

A dual band antenna (AN) configured for being position on a surface of a pit lid and capable of wireless signal transmission at two frequency bands in response to an electrical signal applied via a feed wire. A convex conductive surface, e.g. 5 dome-shaped, is placed above a conductive ground plane element, wherein at least a part of an edge, e.g. 20-40% of the edge, of the dome-shaped radiator element is in electrical contact with the conductive ground plane element. Further, the convex conductive surface is connected via the feed wire. This antenna design allows first and second resonance frequencies within a factor of such as 1.8-2.2, 10 which allows the antenna to be designed e.g. for both of the frequency bands 450-470 MHz and 902-928 MHz which are relevant for meter reading data and with smaller dimension than what could be expected from conventional antennas. A housing with a convex top surface forms an enclosure around the antenna parts conductive ground plane element and the dome-shaped radiator element, the 15 housing has a bottom surface arranged to face the surface of the pit lid, and where the feed wire exits the housing.