Flexible Braids for Improved Magnetic Shielding of Cables

Abstract

Low f r e q u e n c y , magne t ic f i e l d p ic kup in cab les is a severe EMI prob lem. To t e s t the e f f e c t i v e n e s s o f f e r r o m a g n e t i c , amorphous metal a l l o y r ibbons in reducing t h i s problem, b ra id e d s h i e l d s were f a b r i c a t e d and mea­ sured over the f i e l d s t r e n g t h range 0.01 10 Oers ted a t 60 Hz and 400 Hz. Resu l t s show s h i e l d i n g e f f e c t i v e ­ ness in the range 25 dB wh ich i s comparable to b la ck i r o n p ip e , w h i l e a t the same t im e the b ra id s a re f l e x ­ i b l e and l i g h t in w e ig h t .