Shell antenna
The shell antenna is an antenna for microwaves and is one of the reflector antennas .
The reflector of a shell antenna consists of a paraboloid section located far from its axis, which is irradiated by the exciter (usually a horn antenna ) at an angle from outside the direction of radiation. Illumination from below ensures that the parabolic surface itself and the pathogen are protected from precipitation.
The illumination of the dome and thus the directional diagram can be influenced by the design and arrangement of the exciter .
Sometimes metallic side walls reaching up to the paraboloid lead to the paraboloid horn antenna, improve the horizontal directional diagram and stabilize the parabolic surface. By pulling the side walls forward further, the attenuation of the lateral radiation can be increased. The opening in the direction of radiation can be closed with a vertical wall of insulating material, which means that these antennas can be better and more easily protected from precipitation than other antennas.
Shell antennas are used in directional radio wherever high demands on security against eavesdropping, electromagnetic compatibility and weather resistance have to be met, as they have a better directional characteristic than coaxial parabolic antennas .
literature
- Hans Lobensommer: Handbook of modern radio technology. 1st edition, Franzis Verlag GmbH, Poing 1995, ISBN 3-7723-4262-0