| 摘要 |
The flat-topped antenna apparatus includes a GPS antenna, a mobile radio antenna, a common housing for the antennas mounted over a ground plane and coaxial cables (12,13,13a) acting as electrical supply lines for the antennas. The mobile radio antenna includes a metal sheet (6,6',6a) plane parallel to the ground plane and spaced at a distance (A,A') of 0.04 of an average operating wavelength of a mobile radio frequency band from the ground plane. The metal sheet is electrically connected at an input terminal (11) with an inner conductor (10) of one coaxial cable (13,13a) and also with the ground plane via a short circuit element (7,7a). The GPS antenna is above and rests on the mobile radio antenna and includes a dielectric plate (1,1a) provided with a metal layer (3) connected at an input terminal (4) with an inner conductor (10) of another (12) of the coaxial cables. The end points (14,15) of the outer conductors of the coaxial cables located near the respective input terminals (4,11) of both antennas are electrically connected to ground. At least one outer conductor is electrically connected to ground again at a connection point (16) which is located at a distance (d+E,fra 1/4+EE ) of one quarter of the average operating wavelength from the grounded end point of the at least one outer conductor. |
