Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Engineering
Representation Of Gyromagnetic Composite Media For Fdtd Modeling, Marina Koledintseva, James L. Drewniak, Xiaoning Ye
Representation Of Gyromagnetic Composite Media For Fdtd Modeling, Marina Koledintseva, James L. Drewniak, Xiaoning Ye
Electrical and Computer Engineering Faculty Research & Creative Works
A composite media containing particles with a high internal field of magnetic anisotropy (hexagonal ferrites) useful for numerous EMC applications in a wide frequency band is considered. Effective constitutive parameters of a high-loss composite gyromagnetic media are represented in the Lorentzian form. It is convenient for the numerical analysis using the finite-difference time-domain (FDTD) algorithm with a recursive convolution procedure. The equations for the electric and magnetic field updating in such media are represented.
An Emi Estimate For Shielding-Enclosure Evaluation, Min Li, James L. Drewniak, S. Radu, Joe Nuebel, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren
An Emi Estimate For Shielding-Enclosure Evaluation, Min Li, James L. Drewniak, S. Radu, Joe Nuebel, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
A relatively simple, closed-form expression has been developed to estimate the EMI from shielding enclosures due to coupling from interior sources through slots and apertures at the enclosure cavity modes. A power-balance method, Bethe's (1944) small-hole theory, and empirically developed formulas for the relation between radiation, and slot length and number of slots, were employed to estimate an upper bound on the radiated EMI from shielding enclosures. Comparisons between measurements and estimated field strengths suitably agree within engineering accuracy.
Including Smt Ferrite Beads In Dc Power Bus And High-Speed I/O Line Modeling, Jun Fan, Shaofeng Luan, James L. Drewniak
Including Smt Ferrite Beads In Dc Power Bus And High-Speed I/O Line Modeling, Jun Fan, Shaofeng Luan, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
Surface mount technology (SMT) ferrite beads are often used in high-speed digital circuit designs to mitigate noise. The common modeling approach is to include SMT ferrite beads as equivalent lumped LCR circuits. The work presented in this paper included SMT ferrite beads as a frequency-dependent impedance in a PEEC-like modeling tool denoted CEMPIE, a circuit extraction approach based on a mixed-potential integral equation formulation. Agreement with measurements demonstrates the approach. The applications shown are segmentation of power areas for noise isolation, and I/O line filtering.
Investigation Of Pcb Layout Parasitics In Emi Filtering Of I/O Lines, Xiaoning Ye, Geping Liu, James L. Drewniak
Investigation Of Pcb Layout Parasitics In Emi Filtering Of I/O Lines, Xiaoning Ye, Geping Liu, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
EMI filters are often utilized on I/O lines to reduce high-frequency noise from being conducted or coupled off the PCB and resulting in an EMI problem. However, layout parasitics are usually inevitable in practical circuit design, and the filtering performance may vary. In this study, the impact of the board layout on the filtering performance is investigated by |S21| measurements of sample PCB boards with different filter layouts. The finite-difference time-domain method is applied to model the boards, support the experimental work, and can be used to provide a means for conducting "what-if" engineering studies.
Mitigating Power Bus Noise With Embedded Capacitance In Pcb Designs, Minjia Xu, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Mitigating Power Bus Noise With Embedded Capacitance In Pcb Designs, Minjia Xu, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
This paper investigates the power bus noise and power bus impedance of printed circuit boards with four different kinds of embedded capacitance. These boards have power-ground plane pairs separated by a very thin layer of material with high dielectric permittivity. It is shown that embedded capacitance effectively reduces power bus noise over the entire frequency range evaluated (up to 5 GHz).
20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim
20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim
Electrical and Computer Engineering Faculty Research & Creative Works
The 20-H rule is a printed circuit board layout guideline. On boards with power and ground planes, the fringing field at the edges of the board is contained by backing the edge of the power plane away from the edge of the board by a distance equal to 20 times the separation distance between the planes. In this study, test boards were built and measured with and without implementing the 20-H rule. The measured results are compared to numerical models. The results of this study show that, although the near fields are more contained, the radiation from a board implementing …