Compound Broadband EMI Supression Component And Material

The aim of this dissertation is to provide theoretical and experimental evidence for researching and developing new type compound broadband EMI suppression components. To solve problems of narrowing frequency band and poor performance in high frequency of the traditional ferrite EMI suppression components in practical application, a practicable plan will be given base on structure and material. First, effective frequency band of component is widened by compound structure method. Low frequency impedance compound broadband model and high frequency insertion loss compound broadband model is bring forward according to practical situation, then giving corresponding structure and equivalent circuit. After confirming the validity of equivalent circuit, the performance of compound components is measured. The results indicate that models are appropriate. That is to say, compound components have broadband performance. Second, the problem of high frequency poor performance is solved by new material preparation method. After analyzing the limiting factors and the corresponding countermeasure of soft magnetic alloy in high frequency using, design appropriate process of soft magnetic alloy composite material preparation. To optimize preparation method, Micro morphology observe and complex permeability measure are used to analyze samples with different prepare periods and influence of different preparation processes to permeability characteristics is studied. A peculiar twin-peak magnetic resonance broad band dispersion in frequency characteristics of the permeability imaginary part can be obtained by this preparation method, the frequency band of high permeability is reach to several GHz, when 1.2GHz, the μ_r″is 7.3 and μ_r″_max is 14.5。The result of comparative test show that High frequency magnetic performance of this material is excellent than traditional ferrite material and the insertion loss performance of components made of this material is super than ferrite components above several hundreds frequency.