FIELD: radio engineering, communication.
SUBSTANCE: invention relates to low-frequency antenna systems, having improved radiation directivity. The structure and material of the external part of the casing of the antenna are selected such that the ratio of the magnetic permittivity of the external part of the casing to the dielectric permittivity of the external part of the casing remains constant within the external part of the casing and equal to the ratio of the magnetic permittivity of the ambient medium to the dielectric permittivity of the ambient medium. Disclosed low-frequency antenna is designed to emit/receive electromagnetic waves. The antenna includes a feed input which can be connected to a transmission line, an antenna conductor connected to the feed input and a casing which at least partially encloses the antenna conductor. The antenna casing has an internal part which adjoins the antenna conductor and an external part which adjoins the internal part and has a periphery; the internal part of the casing has such a structure or is made from such a material that each of the values of the magnetic permittivity of the internal part of the casing, the conductivity of the internal part of the casing and the dielectric permittivity of the internal part of the casing is constant within the internal part.
EFFECT: designing a low-frequency antenna with improved performance, particularly a wave compression ratio greater than one without changing the full wave impedance of the casing when transitioning from its internal part to its external part.
59 cl, 10 dwg
