Title :
The microwave absorbing phenomena of ferrite microwave absorbers
Author :
Shin, J.Y. ; Oh, J.H.
Author_Institution :
Dept. of Ceramic Eng., Inha Univ., Inchon, South Korea
fDate :
11/1/1993 12:00:00 AM
Abstract :
The complex permeability dispersions and the microwave absorbing phenomena are investigated in ferrite microwave absorbers. The complex permeability of hexagonal (Y- and Z-type) and spinel (NiZn ferrite and NiZnCo ferrite) ferrite microwave absorbers were measured in 200 MHz-16 GHz range. The theoretical matching frequencies are determined by plotting the measured complex permeability loci on the impedance matching solution map. One or two impedance matching phenomena are observed in the ferrite absorbers according to their complex permeability loci on the impedance matching solution map. It was discovered that the first matching frequency (fm1) of the ferrite absorber strongly depends on its spin resonance frequency (fr2) and the second matching frequency (f m2) is independent of the resonance frequency
Keywords :
electromagnetic wave absorption; ferrite devices; impedance matching; magnetic permeability; waveguide components; (NiZnCo)Fe2O4; 200 MHz to 16 GHz; Ba2Ni2Fe12O22; Ni1-xZnxFe2O4; Y-type; Z-type; complex permeability dispersions; ferrite microwave absorbers; hexagonal ferrites; impedance matching solution map; matching frequencies; microwave absorbing phenomena; spin resonance frequency; spinel ferrites; Calcination; Dielectric losses; Ferrites; Impedance matching; Permeability measurement; Permittivity measurement; Powders; Resonance; Resonant frequency; Scattering parameters;
Journal_Title :
Magnetics, IEEE Transactions on
