Dominant factors of electromagnetic interference problems of asymmetrical and equi-distance differential-paired lines

Abstract

Key Points:• The paper focuses on differential-paired lines with equi-distance routing • Characteristics and dominant imbalance and radiation factor is identified • The validity of the equivalent circuit model was demonstrated Supporting Information:• Readme • Figure S1 • Figure S2 • Figure S3 • Figure S4a • Figure S4b • Figure S5a Abstract Multichannel differential signaling scheme is one of the key technologies for modern electronics systems. For actual system, the ideal balance or symmetrical topology cannot be established, and hence, an imbalance component is excited. To provide the basic considerations for electromagnetic (EM) radiation from practical asymmetrical differential-paired lines structure with equi-distance routing, in which the same-length paired lines are used in high-speed board/LSI layout design, in this paper we newly attempt to clarify the characteristics and to identify dominant imbalance and EM radiation factor from asymmetrical differential-paired lines, by a physics-based model. The frequency response of EM radiation from asymmetrical differential-paired lines can be identified using the physics-based model. The physics-based model is constructed with an equivalent circuit model to calculate current distribution, and radiation model based on Hertzian dipole antenna. It is validated by comparing the predicted results with finite difference time domain simulation. This paper reported the basic characteristics of imbalance component of differential-paired lines with asymmetrical equi-distance routing and demonstrates the dominant factor of imbalance component and EM radiation successfully.

Suppression of Mode-Conversion by DNG Material for Differential-Paired Lines with Bend Discontinuities

“…Some previous paper written by the authors [11][12][13] have discussed the correlation between the conversion parameter from balance component (differential-mode: DM) to CM, |S cd21 | and EM from asymmetrical differentialpaired lines. Although equi-distance routing is suitable for the improvement of SI issues, it does not work well for the suppression of the far-field potential radiation.…”