Identifying Frequency Response of EM Radiation from an Asymmetrical Differential-Paired Line based on Physics-Based Equivalent Circuit Model

摘要

Recently, differential-signaling techniques have been widely used in digital electronics devices in order to suppress electromagnetic interference (EMI). But in practical terms, a complete topologically and structurally symmetrical differential-paired lines are impossible. In this paper, we newly attempt to identify and quantify the frequency responses of the imbalance component and electromagnetic (EM) radiation when the structure and topology change from a symmetrical to an asymmetrical differential-paired lines, using a physics-based model, which is constructed with an equivalent circuit model to calculate current distribution, and radiation model based on Hertzian dipole antenna. The physics-based model is validated by comparing the predicted results with FDTD simulation. The frequency response of EM radiation from an asymmetrical differential-paired lines can be identified using our proposed model. This study has successfully established a basic method to effectively predict EM radiation from practical differential-paired lines.