Accession Number : AD0658083

Title :   ABSORPTION AND TRANSMISSION OF ELECTROMAGNETIC WAVES. PHASE C: ABSORPTION OF ELECTROMAGNETIC CM-WAVES IN ANISOTROPIC MEDIA.

Descriptive Note : Final technical rept.,

Corporate Author : GOETTINGEN UNIV (WEST GERMANY) PHYSIKALISCHES INSTITUT

Personal Author(s) : Pottel,Reinhard

Report Date : 31 JUL 1957

Pagination or Media Count : 30

Abstract : With ferrite materials available up to date, equalness of permeability and dielectric constant cannot be achieved for frequencies above 1000 Mc/s without application of static magnetic fields. The reason is given by the large spreading of the natural resonant frequencies of different crystallites or domains. This spreading can be reduced but cannot be completely avoided in principle. Using static magnetic fields, equalness of permeability and dielectric constant in ferrites can be achieved up to frequencies of about 5000 Mc/s. The relative width of the frequency band within which the reflection coefficient is below 0.1 then is about 15%. A widening of this range is necessarily coupled with a reduction of the limiting frequency. For equal permeability and dielectric constant the attenuation along one vacuum wave length at 5000 Mc/s is about 500 dB. Because of the difficulties arising in homogeneously magnetizing larger plates of ferrite material, the discussed method cannot be used for large absorber arrangements. (Author)

Descriptors :   (*ELECTROMAGNETIC RADIATION, ABSORPTION), (*WAVE PROPAGATION, ELECTROMAGNETIC RADIATION), WEST GERMANY, ANISOTROPY, FERRITES, FERROMAGNETIC MATERIALS, PERMEABILITY, DIELECTRIC PROPERTIES, RESONANT FREQUENCY, MAGNETIC FIELDS, ATTENUATION

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE