Flat-top antenna apparatus including at least one mobile radio antenna and a GPS antenna

A flat-topped antenna apparatus comprising an antenna for satellite vehicle navigation (GPS), at least one antenna for mobile radio communication, a housing arranged on a conducting surface, said housing being positioned over said antenna for satellite vehicle navigation and said at least one antenna for mobile radio communication and said conducting surface acting as a ground plane for said antennas, and coaxial cables (12,13,13a) acting as electrical supply lines for said antennas and each comprising an inner conductor (10) and an outer conductor;

• wherein said at least one antenna for mobile radio communication has a substantially circular horizontal radiation diagram and comprises a metal sheet (6,6', 6a) plane parallel to said ground plane, said metal sheet (6,6',6a) is spaced from said ground plane at a distance (A,A') of 0.04 of an average operating wavelength of a mobile radio frequency band used for said mobile radio communication, is electrically connected with the inner conductor (10) of one (13,13a) of said coaxial cables at an input terminal (11) of the metal sheet and is electrically connected with said ground plane by means of at least one short circuit element (7,7a) and an intervening member;
• wherein said antenna for satellite vehicle navigation is above and rests on said at least one antenna for mobile radio communication and comprises a dielectric plate (1,1a) provided with a metal layer (3) and said metal layer (3) is electrically connected with the inner conductor (10) of another (12) of the coaxial cables at an input terminal (4) of the metal layer (3);
• wherein a portion of said inner conductor (10) of said coaxial cable (13,13a) electrically connected to said at least one antenna for mobile radio communication is exposed and passes through a space under said metal sheet (6,6',6a);
• end points (14,15) of the outer conductors of said coaxial cables (12,13,13a) are located in the vicinity of respective ones of said input terminals (4,11) of said antenna for satellite vehicle navigation and said at least one antenna for mobile radio communication;
• said end points (14,15) of the outer conductors are electrically connected to ground;
• and at least one of said outer conductors is electrically connected to ground again at a connection point (16), and said connection point (16) is located at a distance (d.sub.1/4) of one quarter of said average operating wavelength of said at least one antenna for mobile radio communication from said end point (14,15) of said at least one outer conductor.