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Full-Text Articles in Engineering
Analysis Of Radiated Emissions From A Printed Circuit Board Using Expert System Algorithms, Yan Fu, Todd H. Hubing
Analysis Of Radiated Emissions From A Printed Circuit Board Using Expert System Algorithms, Yan Fu, Todd H. Hubing
Electrical and Computer Engineering Faculty Research & Creative Works
Three algorithms developed for expert system electromagnetic compatibility tools are used to evaluate a printed circuit board design. The maximum radiated emissions estimated by the algorithms are compared to the measured data for various board configurations. The algorithms identify the most important electromagnetic interference source mechanisms, drawing attention to the design parameters that have the most significant effect on the radiated emissions.
Radiation Mechanisms For Semiconductor Devices And Packages, Todd H. Hubing, Daryl G. Beetner, Shaowei Deng, Xiaopeng Dong
Radiation Mechanisms For Semiconductor Devices And Packages, Todd H. Hubing, Daryl G. Beetner, Shaowei Deng, Xiaopeng Dong
Electrical and Computer Engineering Faculty Research & Creative Works
VLSI semiconductor devices are often the source of radiated electromagnetic emissions from electronic devices. Noise coupled from these devices to resonant structures on the printed circuit board, resonant cables or resonant enclosures can result in EMI problems that are difficult or expensive to solve at the board or system level. This paper reviews three mechanisms by which noise can be coupled from semiconductor devices and packages resulting in radiated electromagnetic emissions.
Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff
Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
General methods for reducing printed circuit board (PCB) emissions over a broad band of high frequencies are necessary to meet EMI requirements, as processors become faster and more powerful. One mechanism by which EMI can be coupled off a PCB or multichip module (MCM) structure is from high-frequency fringing electric fields on the dc power and reference planes at the substrate periphery An approach for EMI mitigation by stitching multiple ground planes together along the periphery of multilayer PCB power-bus stacks with closely spaced vias is reported and quantified in this paper. Power-bus noise induced EMI and coupling from the …
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.
Emc Analysis Of An 18" Lcd Monitor, Theodore M. Zeeff, Todd H. Hubing, James L. Drewniak, Richard E. Dubroff, Thomas Van Doren
Emc Analysis Of An 18" Lcd Monitor, Theodore M. Zeeff, Todd H. Hubing, James L. Drewniak, Richard E. Dubroff, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
This paper describes a case study covering the evaluation and reduction of the radiated EMI from an 18 inches Liquid Crystal Display (LCD) monitor. The evaluation was completed in two parts: first potential EMI sources at the Printed Circuit Board (PCB) level were identified, then the EMI antennas driven by these sources were analyzed. Methods for reducing the EMI were described in detail, and where applicable, those modifications were applied. Radiated measurements demonstrate the effectiveness of these recommendations.
Designing Power Bus Decoupling For Cmos Devices, S. Radu, Richard E. Dubroff, Todd H. Hubing, Thomas Van Doren
Designing Power Bus Decoupling For Cmos Devices, S. Radu, Richard E. Dubroff, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
The adequacy of the DC power bus decoupling for CMOS devices can be determined if the effective board decoupling capacitance, the CMOS load capacitance, the CMOS power dissipation capacitance, the switching time, and the allowable bus noise voltage are known. A simple method is presented for estimating the effective decoupling capacitance. The load and power dissipation capacitance values are shown analytically and experimentally to be closely related to the transient current. The transient current and switching time are used to estimate the transient noise voltage on the power bus
Effects Of Gapped Groundplanes And Guard Traces On Radiated Emi, D. S. Britt, David M. Hockanson, Fei Sha, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Effects Of Gapped Groundplanes And Guard Traces On Radiated Emi, D. S. Britt, David M. Hockanson, Fei Sha, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
Designers sometimes employ gapped reference planes to isolate analog and digital signals, and separate "quiet" and "noisy" ground structures by providing a series impedance. Guard traces are also used to reduce unwanted coupling to adjacent traces, which can lead to signal integrity or EMI problems. This study investigates the impact of gaps and guard traces on radiated EMI. A simple microstrip circuit was constructed to experimentally analyze the effects of groundplane gaps and guard traces.
Lumped-Element Sections For Modeling Coupling Between High-Speed Digital And I/O Lines, Wei Cui, Hao Shi, Xiao Luo, Fei Sha, James L. Drewniak, Thomas Van Doren, T. Anderson
Lumped-Element Sections For Modeling Coupling Between High-Speed Digital And I/O Lines, Wei Cui, Hao Shi, Xiao Luo, Fei Sha, James L. Drewniak, Thomas Van Doren, T. Anderson
Electrical and Computer Engineering Faculty Research & Creative Works
Lumped-element sections are used for modeling coupling between high-speed digital and I/O lines on printed circuit boards (PCBs) in this paper. Radiated electromagnetic interference (EMI) is investigated when the I/O line going off the board is driven as an unintentional, but effective antenna. Simulated results are compared with measurements for coupled lines. A suitable number of lumped-element sections for modeling is chosen based on the line length and the highest frequency of interest.
Common Mode Currents Induced On Wires Attached To Multilayer Printed Wire Boards With Segmented Ground Planes, R. Lee Hill, Thomas Van Doren, Todd H. Hubing, James L. Drewniak, Franz Gisn
Common Mode Currents Induced On Wires Attached To Multilayer Printed Wire Boards With Segmented Ground Planes, R. Lee Hill, Thomas Van Doren, Todd H. Hubing, James L. Drewniak, Franz Gisn
Electrical and Computer Engineering Faculty Research & Creative Works
An investigation has been undertaken to further study the fundamental mechanisms responsible for inducing high frequency common mode currents on wires attached to multilayer printed wire boards (PWBs). Previous work reported in the EMC literature has demonstrated that the presence of unintended common mode currents on the external cables of electronic equipment is often the primary source of radiated EMI at frequencies above 30 MHz. In an attempt to reduce the magnitude of these currents to yield `quieter' electronic products, many EMC engineers have implemented segmented or `gapped' ground plane geometries in mulilayer PWB designs. The objective of this study …