UHF-WAVEBAND RADIO-ANTENNA ASSEMBLY FOR VEHICLES

摘要

The invention concerns a vehicle-mounted radio-antenna assembly for UHF communications links with land stations. A first antenna element with the character of an electric monopole or dipole with an essentially vertical polarization component is mounted on a first surface, made of essentially homogeneous material, on the vehicle body. Its azimuthal omndirectional properties are considerably affected by the environment formed by the vehicle body. In addition to the first antenna element (3), the assembly includes at least one additional antenna element (8) with monopole or dipole character. Each additional antenna element is mounted either on the first (11) or another (12) surface, and the antenna elements together form an antenna assembly with respect to the antenna-connection point (6). At least one of the antenna elements is directly fed and the other(s) are either directly fed or indirectly fed (passive). The clearance (9) between two adjacent antenna elements is set so that it is smaller than one free-space wavelength.