Waveguide Port Approach in EM Simulation of Microwave Antennas

This chapter generalizes a recently proposed MoM-based approach to waveguide port excitation (WPE) problems on arbitrary conducting and composite geometries. This approach combines the canonical aperture coupling approach with the EFIE-PMCHWT formulation for composite structures. Each WPE problem in this approach is divided into equivalent sub-problems for internal and external regions, which are solved using the MoM. Internal WPE problems are solved using waveguide modal expansion in the port plane, while external problems are solved using the equivalence principle to reduce these problems to the systems of algebraic equations for unknown electric and magnetic currents. The developed approach is validated on radiation and coupling problems for coaxial ports by comparing simulated results with those obtained by other approaches and measurements. An excellent agreement between the simulated and measured results is demonstrated. Finally, this approach is applied to practical EMC problems for microwave antennas fed by coaxial ports

A SPICE Model for IGBTs and Power MOSFETs Focusing on EMI/EMC in High-Voltage Systems

We describe two models of Power Transistors (IGBT, MOSFET); both were successfully used for the analysis of electromagnetic interference (EMI) and electromagnetic compatibility (EMC) while modeling high-voltage systems (PFC, DC/DC, inverter, etc.). The first semi-mathematical–behavioral insulated-gate bipolar transistor (IGBT) model introduces nonlinear negative feedback generated in the semiconductor’s p+ and n+ layers, which are located near the metal contact of the IGBT emitter, to better describe the dynamic characteristics of the transistor. A simplified model of the metal–oxide-semiconductor field-effect transistor (MOSFET) in the IGBT is used to simplify this IGBT model. The second simpler behavioral model could be used to model both IGBTs and MOSFETs. Model parameters are obtained from datasheets and then adjusted using results from a single measurement test. Modeling results are compared with measured turn-on and turn-off waveforms for different types of IGBTs. To check the validation of the models, a brushless DC electric motor test setup with an inverter was created. Despite the simplicity of the presented models, a comparison of model predictions with hardware measurements revealed that the model accurately forecasted switch transients and aided EMI–EMC investigations

Electromagnetic Finite Differences Time Domain (FDTD) Modeling of Partial Discharge Coupling Applied to High Voltage Cables and Cable Joints

This paper analyses the dependence of the output signals from different sensors as a function of partial discharge (PD) location using finite differences time domain (FDTD) modeling and compares their ability to quantify signals to the standard PD measurement method

FDTD Modelling of Nonlinear Spark in Electrostatic Discharge

An accurate numerical method for calculating nonlinear electrostatic discharges is presented. The method represents an improvement over the FDTD scheme in that it includes the arc model of Rompe and Weizel. Numerical results that demonstrate the validity and accuracy of the model are presented

Human Body Impedance Modelling for ESD Simulations

Motivated by understanding the ESD-induced currents from body-worn, wire and hose connected medical equipment is exposed to, a computer simulation is presented to estimate the impedance of a human body relative to ground. This 3D model is the basis for transient field calculation. A Method of Moments (MoM) frequency domain solution is transformed into time domain via IFFT for further circuit level time domain simulations. The human body is modeled as a homogeneous dielectric with frequency-dependent complex permittivity. Dependence of the impedance on the position of discharge and posture of the human body is investigated. The simulation results are compared with measurements and demonstrate capturing of general tendencies of measured curves

Efficient FDTD Simulation of Fields in Coaxial Cables with Multi-Layered Insulation Partially Formed by Dispersive Layers of Extremely High Permittivity

An efficient and accurate FDTD simulation technique for investigation of field propagation in multi-layered coaxial cables has been developed. This technique combines a uniform FDTD scheme with the piecewise linear recursive convolution method, which is applied for the treatment of fields in dispersive layers, having extremely high permittivity. The method has been developed and tested for a radial symmetric cylindrical system and is intended for future use in 3D applications

Calculation of Pulse Propagation in Coaxial Cables with Multi-layered Insulation System

In this paper a simple and efficient method for the calculation of multi-layered coaxial cables is proposed. The parameters of an equivalent transmission line are calculated. These calculations are compared with FDTD results and measurements, and show a good agreement. The developed approach is especially suitable for fast and easy calculation of the propagation characteristics of multi-layered coaxial cables with high permittivity and conductivity, where other methods are less efficient

Simulation of ESD Coupling into Cables Based on ISO 10605 Standard using Method of Moments

ESD events can damage or upset electronic vehicle systems, so discharges to the electronic systems or to the attached cables need to be considered. Discharges to the cables or to coupling structures close to the cables were investigated and a Method of Moments (MoM)-based methodology for ESD simulation is proposed. The simulation results for test benches according to ISO standards were verified against measurements

Broadband Measurement of the Conductivity and the Permittivity of Semiconducting Materials in High Voltage XLPE Cables

The measurement of frequency dependent conductivity and permittivity in semiconducting materials was investigated in the high-voltage cross-linked polyethylene (XLPE) cables. The measurement set up was studied in order to determine the reflection coefficients. The semiconductor sample was analyzed in terms of impedance, calibration, accuracy and temperature control. The temperature dependence of these semiconducting layers of medium and high voltage cables was also reported