This article introduces a comprehensive methodology for analyzing common-mode (CM) ferrite chokes in time-domain (TD) methods, employing lumped dispersive loads, and validates it through a typical test setup for cable crosstalk assessment. The analysis begins with the experimental characterization of CM choke material properties using a coaxial line fixture to obtain its constitutive parameters. Subsequently, a simplified lumped dispersive convolutional model is obtained, representing the impedance of the ferrite when placed on a location on the cable. The first approach adopts a multiconductor transmission line (MTL) model for the cables, solving them by a finite-difference (FDTD) space-time scheme. The second approach utilizes the classical full-wave Yee-FDTD method in conjunction with the thin-wire Holland model for cables. The accuracy of the proposed methods is evaluated by comparing simulations performed with MTL-FDTD and Holland-Yee FDTD, to experimental measurements, and results obtained with the the frequency-domain finite element method using a 3-D model of the ferrite with its constitutive parameters. Finally, the validity and performance of the methodologies are critically discussed.

This article introduces a process to design, simulate, and measure a novel multi-band patch antenna with different operation modes, i.e., band centers and bandwidths. Switching between operation modes is possible using a pair of PIN diodes to connect different parts of the antenna with the main antenna patch. Such a reconfigurable design allows for individual control of each frequency range. The main operation mode of the resulting antenna has an impedance bandwidth with two bands, one from 2.4 GHz to 2.73 GHz and another from 3.4 GHz to 5.73 GHz, with a maximum gain of 4.85 dBi and stable radiation patterns. The resulting antenna is suitable for applications using both ultra-wideband technologies and wireless local-area network (WLAN) technologies.

An impedance model, based on transmission line theory, is introduced for common mode ferrite chokes. The proposed model takes into account the geometrical properties of the choke, the distribution of electromagnetic fields within the core material and the impact of the measurement setup. The validity of the model was tested through numerical simulations. As a practical application, the model was applied to estimate the complex permeability of manganese zinc (MnZn) and nickel zinc (NiZn) cores from impedance measurements, resulting in a range of values compatible with those reported in other works.

We present an accuracy and computational-performance study of Discontinuous Galerkin Time-Domain (DGTD) variants for Maxwell’s equations. The comparison covers: (i) open Legendre–Gauss (LG) versus closed Legendre–Gauss–Lobatto (LGL) nodal bases, (ii) a fully assembled global sparse evolution operator versus a matrix-light connectivity-based (Hesthaven-inspired) operator, and (iii) linear versus second-order curvilinear elements. Validation is performed on three representative benchmarks: (A) a 2D PEC cavity excited with mode TM₅₅, (B) a 2D circular cavity initialized with a Bessel J₆ mode, and (C) the 3D monostatic Radar Cross-Section (RCS) of a PEC sphere to evaluate curved-element benefits against an analytical Mie-series reference. Beyond error convergence, the benchmark sections report representative sparsity through the number of non-zero entries (NNZ), together with the runtime and memory indicators relevant to each comparison. The results show that open and closed bases deliver comparable field accuracy where they are directly compared, while LGL yields systematically sparser operators and, in the reported TM55 and 3D RCS runs, lower memory/runtime cost in the studied high-order regimes. For TM55, open-versus-closed temporal-evolution memory differences reach about 64% at the highest spatially refined case (H3) with a basis order of p = 10, and global-versus-local memory differences reach about 88% in favor of the local operator at the same configuration. Curvilinear elements are essential to remove geometry-induced error floors in curved-domain benchmarks; their computational overhead is benchmark- and configuration-dependent rather than universal. These results provide practical guidance for selecting bases, operators, and geometric representations in large-scale, highfidelity time-domain electromagnetics.