LOW-FREQUENCY ANTENNA

摘要

A low frequency antenna for radiating/receiving an electromagnetic wave is provided. One exemplary antenna comprises a feed port; an antenna conductor connected to the feed port; and an encapsulation at least partially surrounding the antenna conductor. The low frequency antenna comprises different functional materials used in fabrication of the wave-matching encapsulation enclosing the antenna conductor in order to match the wavelength of the compressed wave to the physical size of the resonant antenna, to match the wave impedance within encapsulation and impedance of the outer medium, to enhance the directivity gain by using non-uniform distribution of the material parameters and minimize the intrinsic impedance mismatch between the region of the encapsulation which is forming the compressed wave and the outer medium.

主权项

1. A low frequency antenna for radiating/receiving an electromagnetic wave to/from an outer medium, the antenna comprising:
a feed port connectable to a transmission line; an antenna conductor connected to the feed port; and an encapsulation at least partially surrounding the antenna conductor, wherein the encapsulation has a core part adjacent to the antenna conductor and an external part adjacent to the core part and having a periphery, wherein the core part of the encapsulation has such a structure or is made of such a material that each of the encapsulation core part permeability, the encapsulation core part conductivity and the encapsulation core part permittivity is invariable within the core part, wherein the external part of the encapsulation has such a structure or is made of such a material that at least two of the encapsulation external part permeability, the encapsulation external part conductivity and the encapsulation external part permittivity increases along at least one direction within the external part of the encapsulation from the core part to the periphery of the encapsulation, wherein the structure or material of the external part of the encapsulation is chosen to provide that the ratio of encapsulation external part permeability to the encapsulation external part permittivity is invariable within the external part of the encapsulation and equal to the ratio of the outer medium permeability to the outer medium permittivity.