Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
Electromagnetic noise absorbing material and electromagnetic noise filter
 Electromagnetic noise absorbing material and filter, which are small, light, and effective even with respect to unwanted electromagnetic waves of a few hundred MHz or more, are provided. A small and flexible electromagnetic noise filter cable and tape-shaped electromagnetic noise filter, as well as a manufacturing method and manufacturing apparatus therefor, are also provided. The electromagnetic noise absorbing material has a thickness or particle diameter of the alloy magnetic substance which is within a range of from 1/10 to 10 times the skin depth thereof, and thereby, a large eddy current loss can be generated, so that it is possible to manufacture electromagnetic noise filters having various shapes, which are small, light, and which realize a large electromagnetic noise suppression effect as a result of eddy current loss, and these possess a large relative magnetic permeability even at levels of a few hundred MHz or more. According to the thin film manufacturing method and apparatus, it is possible to easily manufacture an electromagnetic noise absorbing material having small hysteresis, possessing a hard axis of uni-axial magnetic anisotropy, which is superior in high-frequency response, and has a large electromagnetic noise suppression effect. 
Nippon Telegraph and Telephone Corporation
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H01F H01F H05K
additional inventional inventional
Toshinori Masakatsu Osamu Tomoyuki Yasuhiro
Mori Senda Ishii Toshima Koshimoto