Heterotube Mn-Zn Ferrite Bundle EMI Suppressor With Different Magnetic Coupling Configurations

Two types of heterotube ferrite bundle electromagnetic interference (EMI) suppressors were formed using Mn-Zn ferrite tubes with different inner and outer tube diameters. The suppressing principle based on magnetic coupling between the central tube and outer tubes in the bundle, e.g., primary half-turn to different short circuited secondary turns, was applied. Several different configurations, such as meander, frame, chain, cage, and short-circuited turns, were realized for both types of ferrite hetorotube bundle suppressors. They were characterized in the EMI frequency region (1-1000 MHz). The results obtained were compared mutually and with the standard half-turn wire configuration and other round core ferrite tube suppressors. Certain correlations were noticed between changes of characteristic parameter values, such as maximum of impedance Z_m, frequency of maximum impedance F_m, and suppressing range Δf around F_m for all measured configurations. Possible applications as devices suitable for EMI suppressing were considered.