Any radar station (radio, hydro, etc.) can be divided into two parts: a direction finder and processing system which are being synthesized separately.

Receiving signal is a spatial-domain field that is characterized by spatial distribution of energy in accordance with location of objects and interferences masking these objects. Thus a direction finder must include a device that transforms spatial information about object's coordinates containing in the field parameters into electric signal. For radio and hydroacoustic direction finders an antenna is such a device.