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Due to stringent electromagnetic compatibility (EMC) regulations, all electronic devices need to go through rigorous radiated emission tests before launching to market. Thus, efficient, accurate, and cheap characterization approaches are quite of interest. Instead of utilizing the time-consuming and expensive direct far-field measurement, in this work, a novel methodology on the basis of numerical Green’s function (NGF) is proposed to acquire the parasitic EM emissions from PCBs placed in a shielding enclosure with ventilation slots. Referring to Schelkunoff’s equivalence principle, the whole modeling procedure can be decomposed into two steps in order to obtain the emissions in the entire space. For the first step, the tangential electric fields over the surface of ventilation slots are sampled first; then, the NGF over a spherical surface tightly enclosing the perfectly electric conductor (PEC) filled shielding box is numerically evaluated; finally, the tangential component of the magnetic field over the spherical surface enclosing the shielding box is calculated in terms of the NGF and the sampled near electric field. As for the second step, by filling the sphere with a perfectly magnetic conductor (PMC) first, the pertinent Green’s function is further expanded by the spherical modal functions; later, the radiated emission outside this sphere can be analytically evaluated in terms of the previously obtained tangential magnetic field and the modal function expanded Green’s function. Therefore, the novelty of the proposed method has two folds: 1) only the tangential electric field over the ventilation slots is required, thus saving a lot of time in near-field measurement and 2) the NGF is independent of the PCBs in the shielding enclosure and, thus, only needs to be calculated once even though the PCBs inside the shielding enclosure is changed. To validate and verify the effectiveness of this proposed modality, several representative examples are presented. [ABSTRACT FROM AUTHOR]

An early characterization of integrated circuit passive isolation structures is crucial to predict their performance and effectiveness in minimizing substrate coupling. In this paper, an electromagnetic (EM) modeling methodology is proposed, which can be applied to different types of isolation structures based on interference blocking. It consists in characterizing the different doping profiles by identifying those propagation modes with a greater contribution to substrate coupling and to the aggressor-victim transfer function. This allows a fast EM characterization, providing insight on the different isolation mechanisms, identification of transitory effects, and a fast prediction of isolation effectiveness. [ABSTRACT FROM PUBLISHER]

In this paper, we propose the concept and design methodology for a resonant reactive shield for the reduction of magnetic field leakage from a wireless power transfer (WPT) systems. By using LC resonance, the reactive shield can generate a cancelling magnetic field to reduce the incident magnetic field from WPT coils and effectively reduce the total magnetic field without consuming additional power. The shielding effectiveness of the resonant reactive shield and its effect on WPT efficiency are analyzed with simulation and measurements. For practical application to wirelessly charged electric vehicles, an automatic tuning system for the resonant reactive shield is also proposed and implemented. The effectiveness of a resonant reactive shielding is verified by experiments in a wirelessly charged electric bus. [ABSTRACT FROM AUTHOR]

In this paper, the mechanisms that lead to the conversion of common-mode (CM) RF interference (RFI) into differential-mode (DM) disturbances, which corrupt the information content of nominal signals and impair the operation of electronic systems, are investigated. To this purpose, distributed and lumped common-mode into differential-mode (CM-DM) conversion mechanisms are discussed with reference to a simple test structure that can be analytically described. On the basis of the proposed analysis, the origin and the relative impact of such mechanisms is highlighted and the detrimental effect of distributed CM-DM conversion on the effectiveness of differential RFI suppressing filters is discussed. Theoretical predictions are compared with experimental results. [ABSTRACT FROM AUTHOR]

We propose a generalized S-parameter analysis for transmission lines (TLs) with linear/nonlinear load terminations subject to arbitrary plane-wave and port excitations. S-parameters are prevalently used to model TLs such as cable bundles and interconnects on printed circuit boards (PCBs) subject to port excitations. The conventional S-parameter approach is well suited to characterize interactions among ports. However, nontraditional port excitations associated with plane-wave coupling to physical ports at TL terminals lead to forced, as well as propagating, modal waves, necessitating a modification of the standard S-parameter characterization. In this paper, we consider external plane-wave excitations, as well as port (internal) sources, and propose a hybrid S-parameter matrix for characterization of the associated microwave network and systems. A key aspect of the approach is to treat the forced waves at the ports as constant voltage sources and induced propagating modal waves as additional entries (hybrid S-parameters) in the S-parameter matrix. The resulting hybrid S-matrix and voltage sources can be subsequently exported to any circuit solver such as HSPICE and Agilent's Advanced Design System for the analysis of combined linear and nonlinear circuit terminations at ports. The proposed method is particularly suited for susceptibility analysis of cable bundles and PCBs for electromagnetic interference evaluations. It also exploits numerical techniques for structural and circuit domain characterization and allows for circuit design optimization without a need to perform any further computational electromagnetic analysis. [ABSTRACT FROM AUTHOR]

A new efficient hybrid method combining the transmission-line matrix (TLM) and the time-domain method of moments (MoM) is introduced for the accurate modeling of the transient interference between a perfectly conducting thin surface of arbitrary shape and a complex object exhibiting compound with arbitrary electrical properties separated by large free space. For the modeling of the conducting surface, the time-domain electric-field integral equation is used along with the MoM, which relies on a triangular-patch geometrical model of the exterior surface and operates according to the marching-on-in-time technique. The complex inhomogeneous object is modeled by the TLM scheme. The electromagnetic interaction between the objects is provided by the dyadic free-space Green's function in the time domain. To validate this new approach, we have compared the results with those obtained using the pure TLM method. [ABSTRACT FROM AUTHOR]

A time-domain electromagnetic interference (EMI) measurement system allows to reduce measurement time by several orders of magnitude in comparison with conventional systems. This will considerably reduce the costs of compliance tests. In this paper, a novel multiresolution time-domain EMI measurement system is presented. The multiresolution time-domain EMI measurement system exhibits several channels with limiters, amplifiers, and analog-to-digital converters. The amplitude range of the signal is subdivided into several intervals. In each interval the analog-to-digital conversion is performed with an amplitude discretization proportional to the width of the amplitude interval. The signal-to-noise ratio of the multiresolution time-domain EMI measurement system compared with a conventional time-domain measurement system for transient signals is enhanced by at least 50 dB. It is shown that the multiresolution time-domain EMI measurement system has a higher overload factor than conventional systems working frequency domain. The noise floor is 5 dB lower than the noise floor of a conventional EMI receiver. The multi resolution time-domain EMI measurement system shows a higher 1-dB compression point than conventional EMI receivers. Measurements were performed in the frequency range from 30 MHz to 1 GHz and compared with results obtained by an EMI receiver. [ABSTRACT FROM AUTHOR]