Noble magnetic films for effective electromagnetic noise absorption in the gigah

2020-01-30 23:14:10

film method magnetic noise sheet

责任者: Ono, H.;Ito, T.;Yoshida, S.;Takase, Y.;Hashimoto, O.;Shimada, Y. 单位: NEC TOKIN Corp., Sendai, Japan 来源出处: IEEE Transactions on Magnetics(IEEE Trans. Magn. (USA)),2004/07/,40(4):2853-7 摘要: To meet the requirement that radio-frequency (RF) electromagnetic noise absorbers must be very thin to be installed in extremely integrated electronic components, we studied a new type of granular film deposited by coevaporation. The films have a peculiar nanostructure that exhibits a magnetic anisotropy with the easy axis perpendicular to the film plane . In this paper, practical noise suppressing features and advantage of this peculiar nanostructure film are investigated, comparing with a conventional noise suppression sheet made of a composite magnetic material. First, measurements are performed using the microstrip line method , and second with a prototype of digital circuit driven at 50 MHz that produces higher harmonic current noise at frequencies over 1 GHz. In both cases, the films exhibit remarkable ability of noise absorption that suggests high possibility of a thin film absorber which works effectively to suppress noise radiation and transmission from high-speed IC leading to appreciable improvement of RF performance of various electronic components. Numerical analysis based on the finite-difference time-domain (FDTD) method was also performed assuming the noise suppression sheet placed over a microstrip line. The analysis confirmed that re-radiation of electromagnetic noise from the sheet is negligible and it is absorbed mainly by magnetic loss of the sheet material 关键词: amorphous magnetic materials;finite difference time-domain analysis;interference suppression;magnetic anisotropy;magnetic microwave devices;magnetic semiconductors;magnetic thin film devices;microstrip lines;microwave integrated circuits;vapour deposition;magnetic films;electromagnetic noise absorption;gigahertz frequency range;integrated electronic components;granular film;coevaporation;nanostructure;magnetic anisotropy;noise suppression;microstrip line method;digital circuit;harmonic current noise;finite-difference time-domain method;magnetic loss;sheet material;50 MHz