Design of miniaturized common-mode filter by multi-layer low temperature co-fired ceramic

A miniaturized common-mode filter composed of multiple substrates is proposed in this paper. The pattern of each positive coil is interlaced with that of each negative coil, whereby when the positive and negative coils are alternately stacked, the positive coils do not overlap negative coils. With such offset configuration of the coils, the parasitic capacitance introduced between overlapped traces is reduced. So, the thickness of each substrate can be decreased and the size of the entire filter is effectively reduced. Good agreements between simulated and measured results are demonstrated. Further, the effectiveness of this filter is revealed by radiation spectrum measurements.

[1]  C. Paul.  Introduction to electromagnetic compatibility , 2005 .

[2]  Frank J. Tilley.  Reducing radiated emissions on high speed signal lines using common mode choke coils , 1995, Proceedings of International Symposium on Electromagnetic Compatibility.

[3]  Kiyohito Yamasawa,et al.  A New Multilayered Common-Mode Filter on Ni-Zn , 2001 .

[4]  S. Daijavad,et al.  Modeling common-mode radiation of 3D structures , 1992 .

[5]  W. Eisenstadt,et al.  Combined differential and common-mode scattering parameters: theory and simulation , 1995 .

[6]  C. R. Paul,et al.  Effect of an image plane on printed circuit board radiation , 1990, IEEE International Symposium on Electromagnetic Compatibility.

[7]  J. D. Gavenda.  Measured effectiveness of a toroid choke in reducing common-mode current , 1989, National Symposium on Electromagnetic Compatibility.

[8]  F. Tsuda,et al.  Development of common mode filter with a multilayer structure , 1999, 1999 International Symposium on Electromagnetic Compatibility (IEEE Cat. No.99EX147).

[9]  Clayton R. Paul.  A comparison of the contributions of common-mode and differential-mode currents in radiated emissions , 1989 .

[10]  Madhavan Swaminathan,et al.  Characterization of embedded passives using macromodels in LTCC technology , 1998 .

[11]  J.M. Wu,et al.  A novel modified-T equivalent circuit for modeling LTCC embedded inductors with a large bandwidth , 2003, IEEE MTT-S International Microwave Symposium Digest, 2003.

[12]  K. B. Hardin,et al.  Decomposition of radiating structures using the ideal structure extraction methods (ISEM) , 1993 .