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Full-Text Articles in Engineering
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 …
Quantifying Smt Decoupling Capacitor Placement In Dc Power-Bus Design For Multilayer Pcbs, Jun Fan, James L. Drewniak, James L. Knighten, Norman W. Smith, Antonio Orlandi, Thomas Van Doren, Todd H. Hubing, Richard E. Dubroff
Quantifying Smt Decoupling Capacitor Placement In Dc Power-Bus Design For Multilayer Pcbs, Jun Fan, James L. Drewniak, James L. Knighten, Norman W. Smith, Antonio Orlandi, Thomas Van Doren, Todd H. Hubing, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
Noise on a dc power-bus that results from device switching, as well as other potential mechanisms, is a primary source of many signal integrity (SI) and electromagnetic interference (EMI) problems. Surface mount technology (SMT) decoupling capacitors are commonly used to mitigate this power-bus noise. A critical design issue associated with this common practice in high-speed digital designs is placement of the capacitors with respect to the integrated circuits (ICs). Local decoupling, namely, placing SMT capacitors in proximity to ICs, is investigated in this study. Multilayer PCB designs that employ entire layers or area fills for power and ground in a …
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.
Emi Considerations In Selecting Heat-Sink-Thermal-Gasket Materials, Yu Huang, J. E. Butler, M. De Sorgo, Richard E. Dubroff, Todd H. Hubing, James L. Drewniak, Thomas Van Doren
Emi Considerations In Selecting Heat-Sink-Thermal-Gasket Materials, Yu Huang, J. E. Butler, M. De Sorgo, Richard E. Dubroff, Todd H. Hubing, James L. Drewniak, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
Specific design criteria are proposed to mitigate radiated emissions from a resonant enclosure excited by a heat sink acting as a microstrip patch antenna source. In this particular application, the EMI mechanism is assumed to be due to coupling from the dominant TMz010 mode to one or more resonant modes associated with the enclosure dimensions. The enclosure is then presumed to radiate, at the enclosure resonance frequencies, through one or more apertures, slots, or seams. The EMI-reduction strategy consists of shifting the resonant frequency of the dominant-patch antenna mode by dielectrically loading the patch antenna with thermal-gasket material …
Fdtd And Experimental Investigation Of Emi From Stacked-Card Pcb Configurations, David M. Hockanson, Xiaoning Ye, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff
Fdtd And Experimental Investigation Of Emi From Stacked-Card Pcb Configurations, David M. Hockanson, Xiaoning Ye, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
Stacked-card and modules-on-backplane printed circuit-board geometries are advantageous for conserving real-estate in many designs. Unfortunately, at high frequencies, electromagnetic magnetic interference (EMI) resulting from the nonnegligible impedance of the signal return at the connector may occur. This effective EMI coupling path results in the daughtercard being driven against the motherboard and attached cables, resulting in common-mode radiation. The connector geometry can be modified to minimize the EMI coupling path when high frequencies are routed between the motherboard and daughtercard. Current speeds and printed circuit board (PCB) sizes result in geometries that are of significant dimensions in terms of a wavelength …
Estimation Of Printed Circuit Board Power Bus Noise At Resonance Using A Simple Transmission Line Model, H. Hu, Todd H. Hubing, Thomas Van Doren
Estimation Of Printed Circuit Board Power Bus Noise At Resonance Using A Simple Transmission Line Model, H. Hu, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
The maximum coupling between printed circuit board components connected to the same power-ground plane pair often occurs at or near power bus resonances. Theoretically, the transfer coefficient, S 21 , between two locations on the power bus can be as high as 0dB (i.e. perfect coupling) near resonant frequencies. However, in practice the coupling is usually much less due to losses in the power bus structure. Determining exactly what the maximum coupling will be in a lossy power bus structure requires a numerical model or measurement. However, an estimation of the maximum coupling can be obtained by drawing an analogy …