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Electrical and Computer Engineering
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Full-Text Articles in Engineering
Investigation Of Internal Partitioning In Metallic Enclosures For Emi Control, S. Radu, Min Li, Joe Nuebel, David M. Hockanson, Yun Ji, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Investigation Of Internal Partitioning In Metallic Enclosures For Emi Control, S. Radu, Min Li, Joe Nuebel, David M. Hockanson, Yun Ji, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
High clock frequencies and short-edge rates in present high-speed digital systems result in EMI problems at increasingly higher frequencies. At these speeds, clock harmonics have sufficient energy in the range above 500 MHz to excite cavity modes of a conducting enclosure, and to drive even small length slots and apertures that are unavoidable in a practical design, and can result in an EMI problem. One approach to mitigate these problems is to partition the enclosure into several smaller internal shielded compartments. To study the factors which affect this partitioning, a special enclosure that can be divided into two internal compartments …
An Expert System For Predicting Radiated Emi From Pcb's, Navin Kashyap, Todd H. Hubing, James L. Drewniak, Thomas Van Doren
An Expert System For Predicting Radiated Emi From Pcb's, Navin Kashyap, Todd H. Hubing, James L. Drewniak, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
This paper describes an expert systems approach, based on symbolic reasoning techniques, to the problem of predicting radiated EMI levels from printed circuit boards. The expert system, currently under development at the University of Missouri-Rolla, USA, starts by extracting board geometry information from the board layout files. This information is fed into the classification algorithm, which determines the signal properties and nature of each net, using the knowledge stored in the knowledge base. The evaluation algorithm uses the available in formation to identify and evaluate critical circuit geometries, and then estimates the effect that these geometries have on system radiation …
Investigation Of Split Groundplanes At The Connector For Emi Control, David M. Hockanson, James L. Drewniak, Joe Nuebel, James C. Parker Jr.
Investigation Of Split Groundplanes At The Connector For Emi Control, David M. Hockanson, James L. Drewniak, Joe Nuebel, James C. Parker Jr.
Electrical and Computer Engineering Faculty Research & Creative Works
EMI can often be reduced by selectively filtering various parts of a given system. One common method employed by designers is to split the groundplane near the chassis and route I/O lines over the split. The rationale is based on providing a large series impedance to common-mode currents on the I/O lines. In this manner, PCB designers hope to lower the level of noise currents contributing to radiation. This work studies the efficacy of the groundplane split as a deterrent for EMI associated with I/O lines being driven against other extended reference structures. A test-board was developed to analyze the …
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.
Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, Min Li, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, Min Li, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
Subcellular modeling of thin slots in the finite-difference time-domain (FDTD) method is investigated. Two subcellular algorithms for modeling thin slots with the FDTD method are compared for application to shielding end osures in electromagnetic compatibility (EMC). The stability of the algorithms is investigated, and comparisons between the two methods for slots in planes, and slots in loaded cavities are made. Results for scattering from a finite-length slot in an infinite plane employing one of the algorithms are shown to agree well with published experimental results, and power delivered to an enclosure with a slot agree well with results measured for …