In telecommunication, antenna blind cone (sometimes called a cone of silence) is the volume of space, usually approximately conical with its vertex at the antenna, that cannot be scanned by an antenna because of limitations of the antenna radiation pattern and mount.
Note: An example of an antenna blind cone is that of an air route surveillance radar (ARSR). The horizontal radiation pattern of an ARSR antenna is very narrow. The vertical radiation pattern is fan-shaped, reaching approximately 70° of elevation above the horizontal plane. As the antenna is rotated about a vertical axis, it can illuminate targets only if they are 70° or less from the horizontal plane. Above that elevation, they are in the antenna blind cone.
Blind Trust is a publication of the non-profit organization RADAR (Radio Association Defending Airwave Rights, Inc.).
In the first instance, the reading was caused by panning the radarantenna and in the second, the radar unit was measuring the fan motor in the patrol car.
Because traffic radar is "direction blind," differences in reflectivity may cause instant-on readings to display the speed of a receding vehicle rather than of an approaching vehicle.
An antenna in electronics (aerial in British English) is an arrangement of conductors designed to radiate an electromagnetic field in response to an applied alternating electromotive force (EMF) and the associated alternating electric current.
Antennae have practical use for the transmission and reception of radio signals, which can pass through (nonconducting) walls at the speed of light over great distances.
A dielectric resonator is a variation on the conventional antenna in which an insulator with a large dielectric constant is used to modify the electromagnetic field.
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