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The Holland and Simpson thin wire formalism permits arbitrarily thin wires to be accounted for in the finite-difference time-domain (FDTD) method. However, it is known that a parasitic solution may be added to the physical solution when the wires are not parallel to the axes of coordinates. In this paper, we show that the spurious parasitic solutions originate in the distribution of the currents of the wires in the FDTD grid, which may produce nonphysical deposit of electric charges. A condition not to produce spurious solutions is derived, and an implementation of oblique wires that satisfies the condition is presented. Numerical experiments demonstrate the absence of parasitic solution. [ABSTRACT FROM AUTHOR]

This paper presents experimental results obtained from the Guangdong comprehensive observation experiment on lightning discharge during summer 2014. Residual voltages and current flows in a surge protective device (SPD) connected to an overhead distribution line were observed due to nearby M-components of a triggered lightning flash. Residual voltages with varying characteristics caused by different M-components are analyzed at two terminals of the SPD, and corresponding formation mechanisms for the different characteristics are also discussed. Our results show that the residual voltages at two terminals of the SPD caused by three types of M-component are determined from both the line induction and the ground potential rise (GPR) in a nearby triggered lightning at 40 m distance. The M-component with a large peak current would produce large surge energies in the power line. Under a given peak current, the M-component has greater surge energy than the return stroke. The ground terminal of the SPD is still affected by the GPR, and our results also show that the continuing current superimposed with M-components is an important factor in determining the magnitude of line coupling in power distribution lines when a lightning flash occurs nearby. [ABSTRACT FROM PUBLISHER]

The validity of the Rusck coupling model and its equivalence to the model by Agrawal, Price and Gurbaxani have already been demonstrated for the case of a perfectly conducting ground and a vertical stroke channel. However, in spite of its popularity, the restriction of an infinite soil conductivity imposes a strong limitation on the use of the model for the analysis of realistic situations. In this paper, a procedure is proposed to extend the Rusck's model to the case of a finite ground conductivity so as to enable the calculation of lightning-induced transients on overhead lines taking into account the soil electrical parameters. The validity of the model is demonstrated through comparisons of simulation results with measured lightning-induced voltages and currents obtained from scale model and rocket-triggered lightning experiments. [ABSTRACT FROM PUBLISHER]

Supply noise is conventionally modeled as a fixed voltage noise specification. Modern integrated circuit design cannot meet a conventional fixed voltage noise specification due to large dynamic noise. These days, applications of multicore system-on-chip (SoC) and multichip system-in-package become very common. The impact of dynamic noise can be even more detrimental for multicore or SoC design as supply noise can be completely uncorrelated between two regions whose powers are different. Accurate modeling of noise impact requires a new approach that can account for any jitter tracking in clock forwarding systems. In this paper, a comprehensive dynamic noise modeling methodology is presented to analyze jitter impact in various clock forwarding interfaces for multicore and SoC designs. The proposed method uses the frequency-dependent jitter sensitivity function with a noise spectrum to model the desired jitter tracking. [ABSTRACT FROM AUTHOR]

As we know, air breakdown would occur if the power of a microwave pulse, which radiates from an aperture antenna, was high enough, the transmission of microwave could be hindered. Based upon this assumption, this paper intends to report on the mathematical deduction of the maximum power radiated from an aperture antenna before air breakdown in the near-field region. It also presents the calculations in the power density enhancement factors corresponding to different kinds of aperture field distributions in the near-field region of a circular cophasal aperture. In addition, this paper also proposes a formula by the field equivalence principle for calculating the normalized power density on axis. The results showed that the air breakdown in the near-field region could be a limiting factor for the maximum power, depending on aperture radius, the field distribution in the aperture plane, the frequency, and the pulse width of a microwave pulse. [ABSTRACT FROM PUBLISHER]

This paper proposes an analytical formula for calculating lightning-induced voltages on an infinitely long overhead line generated by a lightning stroke departing from an arbitrary altitude. A calculation method of the lightning-induced voltages to consider various engineering return-stroke models that can account for the variation of both current amplitude and velocity in a lightning channel is proposed. The lightning stroke is divided into a number of segments, and the analytical formula of the lightning-induced voltage is applied to each segment. This paper discusses the influence of parameters of return-stroke models on lightning-induced voltages. The proposed method is applied to a case of lightning strike to a tall stack. [ABSTRACT FROM AUTHOR]

In high-speed multilayer printed circuit boards, gaps are commonly used in planes, where different areas are utilized for different logic levels or where noise isolation from one area to another is necessary. However, these gap structures could present serious signal integrity and electromagnetic interference issues. In this paper, an extended cavity method is developed to characterize noise coupling caused by slots or gaps in the middle plane of a three-plane structure. According to the equivalence principle, the entire structure can be divided into two plane pairs without any slot in the middle plane, and then, equivalent magnetic currents are needed in both plane pairs in the slot region to retain the same field distributions. Dyadic Green's functions of a rectangular cavity with perfect electric conductor top and bottom surfaces and perfect magnetic conductor sidewalls are derived for both electric and magnetic current excitations. Magnetic auxiliary ports with “magnetic voltage” and “magnetic current” are defined in the slot region to enable vertical connections of two plane pair. The conventional cavity model and segmentation technique are extended in this paper to handle such magnetic auxiliary ports. The proposed method can be used to effectively analyze the apertures with arbitrary shapes and is validated by full-wave simulations. [ABSTRACT FROM AUTHOR]

This paper presents efficient algorithms for sensitivity calculations of power delivery network (PDN) impedance. The sensitivity algorithm is based on the adjoint system method. Efficient calculation of sensitivity is critical for optimization of complex PDNs. The frequency-domain design of a PDN is a multiobjective optimization problem, which is formulated as a minimax problem in this paper. The design variables are typically the decoupling capacitors (decaps). The objective function is the input impedance of the PDN calculated at relevant frequencies. This paper also presents an efficient algorithm for large-change sensitivity calculations. Based on this method, what-if scenarios can be simulated efficiently, such as the addition, modification, or relocation of a few decaps or a small change in the geometry. [ABSTRACT FROM AUTHOR]

This paper presents analytical formulas for lightning-induced surges (voltage and current) on an infinite length of overhead line, which are generated by a nearby lightning stroke with arbitrary striking angle. The formulas are derived using the Rusck model, which is one of the electromagnetic coupling models based on a transmission-line approximation of a return stroke. The return-stroke current is approximated by piecewise linearly varying characteristics. The formulas are simple and convenient for lightning-induced effect analysis. The analytical formulas are validated by the comparison with a finite-difference method. The paper proposes approximate formulas of peak value and time to peak value of the lightning-induced voltages for a vertical lightning channel. [ABSTRACT FROM AUTHOR]

In recent work, we derived generalized sheet transition conditions (GSTCs) for the average (or "macroscopic") electromagnetic fields across a metaflim, which, when properly designed, can have certain desired reflection and transmission properties. A metafilm is the two-dimensional equivalent of a metamaterial, and is essentially a surface distribution of electrically small scatterers characterized by electric- and magnetic-polarizability densities. In this paper, the GSTC is used to calculate the reflection and transmission coefficients of the metafilm. These coefficients are derived for both TM and TE polarized plane waves with arbitrary incidence angles. We show that the reflection and transmission properties of the metaflim are expressed in terms of the electric and magnetic polarizabilities of the scatterers themselves, and we derive conditions on the polarizabilities of the scatterers required to obtain total transmission and/or total reflection. We show various examples to illustrate the validity of the GSTC for the analysis of a metafilm. By controlling the polarization densities of the scatterers in the metafilm, a "smart" and/or "controllable" surface can be realized. We propose a metafilm composed of spherical magneto-dielectric particles for achieving such a controllable surface. To validate the results for the spherical particle metafilm, we show comparisons with a full-wave computation obtained from a mode-matching technique applied to the doubly infinite array of spherical scatterers. The results in this paper are in principle scalable; that is, the dimensions of the scatterers can range from relatively large to relatively small depending on the frequencies of interest. [ABSTRACT FROM AUTHOR]

High-power electromagnetic (HPEM) signals are a serious threat for modern electronic systems. Intentionally generated electromagnetic interferences might cause upsets or permanent defects in electronics, particularly in the electronics' interface. There are numerous military and especially civil targets, which might be interesting for criminals or terrorists to interfere. Therefore, there is a need to characterize the overall problem by means of simulations and measurements. This paper discusses measurement procedures for conducted HPEM signals. The measurement of transmission line coupled HPEM signals with a steepness in the order of 10.10E14 V/s is a very challenging task. This paper discusses the state of the art in electromagnetic pulse measurements with a focus on conducted ultra wide band and HPEM signals respectively. [ABSTRACT FROM AUTHOR]

This paper presents a procedure for evaluation of lightning performance of overhead distribution lines. Because both voltages from direct strokes and nearby strokes may cause flashovers in distribution lines, flashover rates due to them need to be analyzed. The procedure is implemented in electromagnetic transient program, and the Monte Carlo method is used to take into account the random nature of lightning parameters. The lightning-induced voltages are calculated with an equivalent circuit derived from Agrawal formula. The influence of insulation level and spacing between surge arresters on lightning flashover rates is analyzed with the procedure. For a line with low-insulation level about 150 kV above high conductivity ground or with high-insulation level about 300 kV above low conductivity ground, the spacing between arresters is best less than 400 m. But for a line with low-insulation level above low conductivity ground, it is better to reduce the spacing to 200 m. [ABSTRACT FROM AUTHOR]

Electric supply reliability is an issue of wide importance to both an information-oriented society and electric power companies. This paper focuses on lightning effects on distribution lines. Field research is now underway in the northern part of the Kanto Plain in Japan, and voltage and current waveforms in distribution lines due to lightning hits have been observed since 1996. There are now 284 datasets; these include data on 62 direct flashes to lines. This research reveals that a distribution line can be protected from direct lightning strokes. In some cases, no power follow current was confirmed after a multiple phase flashover, and a statistical analysis was conducted to investigate factors affecting the generation of power follow current. These results can serve as a valuable resource to help clarify the mechanisms underlying the production of distribution-line faults caused by lightning effects. [ABSTRACT FROM AUTHOR]

This paper provides a novel iterative solution in an analytical (as opposed to numerical) fashion in the frequency domain for crosstalk on multiconductor transmission lines. The proposed method employs the distributed analytical representation of equivalent coupling sources and an iterative technique originated in transverse waveform relaxation. The effects of adjacent lines at each iteration are considered as equivalent distributed sources along the lines rather than lumped sources at the end of the lines or segments. By means of combined voltage waves, these equivalent distributed sources are further implemented analytically in the form of exponential function combinations, leading to a more efficient updating process since the time-consuming numerical integration over the line is avoided. The voltages and currents at the terminals are solved by the Baum–Liu–Tesche equation considering the symmetry of the coupled transmission lines. One major advantage is that the solution at each iteration is obtained analytically and exactly in terms of the per-unit-length parameters, loads, and some predetermined coefficients, which is highly suitable for illustrating the factors that influence the crosstalk. The validation results in a wide range cases show that the proposed method can efficiently handle transmission lines with a large number of conductors and lossy as well as frequency-dependent parameters. [ABSTRACT FROM PUBLISHER]

To supply high-speed digital circuits with stable power, power/ground noise, such as simultaneous switching noise (SSN) and ground bounce noise caused in multilayer printed circuit boards (PCBs) and packages need to be sufficiently suppressed. The electromagnetic bandgap (EBG) is widely recognized as a good solution for suppressing the propagation of SSN in the gigahertz range. However, a typical coplanar EBG structure etched onto the power and ground planes may degrade the quality of high-speed signals passing over the perforated reference plane. In this paper, a novel method of arranging EBG unit cells on both the power/ground planes in multilayer PCBs and packages is proposed, not only as a means of sufficiently suppressing the propagation of power noise, but also as a means of minimizing the effect of EBG-patterned reference planes on a high-speed signal. On the assumption that noise sources and noise-sensitive devices exist only in specific areas, the proposed method partially positions EBG unit cells only near these critical areas. The SSN suppression performance of the proposed structure is verified by conducting simulations and measurements in the time and frequency domains. Furthermore, signal quality is investigated to verify whether the proposed EBG-patterned reference planes are superior to conventional EBG-patterned planes in terms of signal integrity. [ABSTRACT FROM AUTHOR]

After providing an overview of the state-of-the-art in power distribution design and modeling, this paper focuses on return path discontinuities (RPDs) for I/O signaling. After briefly describing their importance in the context of simultaneous switching noise, a specific case of RPD based on via discontinuities is discussed in detail in the context of both the frequency- and time-domain waveforms using a test vehicle. The modeling of RPD in practical packages and printed circuit boards is addressed along with substrate coupling due to nonideal reference planes. Finally, a high-impedance power distribution scheme for I/O signaling is presented that can potentially solve a number of RPD-related problems, followed by future challenges. [ABSTRACT FROM AUTHOR]

Mitigating power distribution network (PDN) noise is one of the main efforts for power integrity (PI) design in high-speed or mixed-signal circuits. Possible solutions, which are based on decoupling or isolation concept, for suppressing PDN noise on package or printed circuit board (PCB) levels are reviewed in this paper. Keeping the PDN impedance very low in a wide frequency range, except at dc, by employing a shunt capacitors, which can be in-chip, package, or PCB levels, is the first priority way for PI design. The decoupling techniques including the planes structure, surface-mounted technology decoupling capacitors, and embedded capacitors will be discussed. The isolation approach that keeps part of the PDN at high impedance is another way to reduce the PDN noise propagation. Besides the typical isolation approaches such as the etched slots and filter, the new isolation concept using electromagnetic bandgap structures will also be discussed. [ABSTRACT FROM AUTHOR]

The validity domain of the quasi-static method for computation of high frequency and transient characteristics of horizontal buried wires can be established by comparison with an exact analytical method. Usually, limitations of the quasi-static method are derived for practical characteristics, but these are strongly dependent on the specific case and computed quantities. This paper presents an analysis of the differences in the application of the exact and quasi-static Green's function in a method of moments approach for two important cases: distribution of currents in directly fed wires and induced currents in passive wires. It is concluded that the validity domains of the quasi-static method in these two cases are very different. [ABSTRACT FROM AUTHOR]

A hybrid scattering matrix method (SMM) and a modal decomposition technique for analysis of signal traces in the power distribution network of an electronic package are presented in this paper. Applying the modal decomposition of the waves propagating inside the power-ground (P-G) planes and the signal traces, the electromagnetic fields can be decomposed into the parallel-plate mode and the transmission-line mode. The former is analyzed by using the SMM for the finite P-G planes with multiple vias. The multiconductor transmission-line theory is applied to model the micro-stripline and stripline in the package. Numerical simulations are illustrated for coupling analysis of P-G vias to the signal traces in the package and examined through experimental and numerical validations. [ABSTRACT FROM AUTHOR]

A test airport runway lighting system, including a buried cable protected by a counterpoise and vertical ground rods, was subjected to direct lightning strikes, and currents and voltages measured in different parts of the system were reported earlier by Bejleri et al. In this paper, we attempt to model the lightning interaction with this system using the transmission line theory. Lumped devices along the cable such as current regulator and transformers are ignored; possible nonlinear phenomena (arcing) in the system are neglected; the soil is assumed to be homogeneous. The model-predicted currents in the counterpoise, ground rod, and the cable are compared with the measurements, and a reasonable agreement was found for the currents along the counterpoise. It is found that current in the counterpoise is not much influenced by the presence of the cable. Further, vertical ground rods connected to the counterpoise do not have significant influence on the current distribution along the counterpoise. It appears that the model is unable to predict cable currents and voltages in the test system, presumably due to neglecting nonlinear phenomena in the soil and in cable's insulation and electromagnetic coupling with the lightning channel. [ABSTRACT FROM AUTHOR]

As layout density increases in highly integrated multilayer printed circuit boards (PCBs), the noise that exists in the power distribution network (PDN) is increasingly coupled to the signal traces, and precise modeling to describe the coupling phenomenon becomes necessary. This paper presents a model to describe noise coupling between the power/ground planes and signal traces in multilayer systems. An analytical model for the coupling has been successfully derived, and the coupling mechanism was rigorously analyzed and clarified. Wave equations for a signal trace with power/ground noise were solved by imposing boundary conditions. Measurements in both the frequency and time domains have been conducted to confirm the validity of the proposed model. [ABSTRACT FROM AUTHOR]

Due to the rapid surge in operating frequencies and complexity of modern electronic designs, accurate/fast electromagnetic compatibility/interference analysis is becoming mandatory. This paper presents a closed-form SPICE macromodel for fast transient analysis of lossy multiconductor transmission lines in the presence of incident electromagnetic fields. In the proposed algorithm, the equivalent sources due to incident field coupling have been formulated so as to take an advantage of the recently developed delay extraction based passive transmission line macromodels. Also, a method to incorporate frequency-dependent per-unit-length parameters is presented. The time-domain macromodel is in the form of ordinary differential equations and can be easily included in SPICE like simulators for transient analysis. The proposed algorithm while guaranteeing the stability of the simulation by employing passive transmission line macromodel, provides significant speed-up for the incident field coupling analysis of multi-conductor transmission line networks, especially with large delay and low losses [ABSTRACT FROM AUTHOR]

In this paper, the telegrapher equations are extended to general modes and very high frequencies to include radiation effects. it is shown, that the new line parameters are gauge dependent. However, there is also a gauge-independent representation of these parameters. In this representation, the per-unit-length capacitance is not correlated with the radiation resistance, only the per-unit-length inductance (strictly speaking, the imaginary part of it) constitutes it. The generalization to multiconductor and to finite straight transmission lines is straightforward. [ABSTRACT FROM AUTHOR]

This paper discusses the mathematical modeling of the propagation of electromagnetic energy along nonuniform transmission lines. This electromagnetic energy can either be transmitted signals or disturbances caused by electromagnetic interference. Emphasis is laid on the basic ideas behind the transmission-line super theory and the solution of the corresponding telegrapher equations. We show how to establish these telegrapher equations for nonuniform transmission lines and how to calculate the per-unit-length parameters. Afterwards we discuss several solution methods, like numerical integration techniques and semi-analytical approaches. With selected examples we demonstrate the application of our new tools. [ABSTRACT FROM AUTHOR]

In multilayer printed circuit boards, the noise on the power bus is influenced by the impedance between the power and ground planes. Power-bus noise estimates require an accurate estimate of the power-bus input impedance. This paper develops a closed-form estimate of the input impedance for circular power-return plane structures. When the structure is lossy (e.g., boards employing embedded capacitance or densely populated boards), the energy reflected from the board edge does not significantly affect the input impedance. In general, the expressions developed here for circular structures can be used to estimate the impedance of lossy power-return plane structures of any shape. [ABSTRACT FROM AUTHOR]

The net ground plane inductance of printed circuit boards is the source of common-mode radiated emissions. Correct determination of the net ground plane inductance provides a quick estimation of the radiated emissions from printed circuit boards. Employing conformal mapping technique, this paper gives a closed-form expression for the per unit length net ground plane inductance of coplanar stripline printed circuit boards with finite ground plane width. Current density distribution on the ground plane is also obtained. [ABSTRACT FROM AUTHOR]