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Full-Text Articles in Engineering
Estimation Of Current From Near-Field Measurement, Haixiao Weng, Daryl G. Beetner, Richard E. Dubroff, Jin Shi
Estimation Of Current From Near-Field Measurement, Haixiao Weng, Daryl G. Beetner, Richard E. Dubroff, Jin Shi
Electrical and Computer Engineering Faculty Research & Creative Works
Knowledge of high-frequency currents in the chip and chip-package are necessary for EMI analysis and prediction, though measurement of these currents may be difficult to obtain in many cases. One possibility is to estimate currents from near-field scan data. In this paper, measurements were made of the magnetic field over a simple circuit and a chip package. The current flowing in the circuit and the chip lead frame was estimated from the compensated near-field data and compared with measurements made directly on the pins. Estimation was performed both with and without structural information of the lead frame. The susceptibility of …
Coupling Between Differential Signals And The Dc Power-Bus In Multilayer Pcbs, Chen Wang, Marco Leone, James L. Drewniak, Antonio Orlandi
Coupling Between Differential Signals And The Dc Power-Bus In Multilayer Pcbs, Chen Wang, Marco Leone, James L. Drewniak, Antonio Orlandi
Electrical and Computer Engineering Faculty Research & Creative Works
Differential and common-mode transfer impedances are proposed herein to analyze noise coupled to (from) the dc power-bus from (to) via transitions in differential signals. Expressions for the two transfer impedances in terms of conventional single-ended transfer impedances are derived and verified through measurements, full-wave finite-difference time-domain (FDTD) simulations and an analytical cavity model. Some properties of the differential and common-mode transfer impedances are investigated to facilitate engineering design. The impact of signal current imbalances on power-bus noise and the benefit of differential signals as compared to single-ended signals are quantified.
Calibration And Compensation Of Near-Field Scan Measurements, Masahiro Yamaguchi, Richard E. Dubroff, Kevin P. Slattery, Michael A. Cracraft, Jin Shi
Calibration And Compensation Of Near-Field Scan Measurements, Masahiro Yamaguchi, Richard E. Dubroff, Kevin P. Slattery, Michael A. Cracraft, Jin Shi
Electrical and Computer Engineering Faculty Research & Creative Works
A procedure for the calibration and compensation of near-field scanning is described and demonstrated. Ultimately, the objective is to quantify the individual field components associated with electromagnetic interference (EMI) from high speed circuitry and devices. Specific examples of these methods are shown. The effects of compensation are small but noticeable when the uncompensated output signal from near field scanning is already a very good representation of the field being measured. In other cases, the improvement provided by compensation can be significant when the uncompensated output signal bears little resemblance to the underlying field.
Emi Specifics Of Synchronous Dc-Dc Buck Converters, Zhe Li, David Pommerenke
Emi Specifics Of Synchronous Dc-Dc Buck Converters, Zhe Li, David Pommerenke
Electrical and Computer Engineering Faculty Research & Creative Works
DC-DC buck converter topology is widely used in computers and telecom applications because of its high power efficiency and multiple DC levels. However, EMI can be an issue because of its fast switching characteristics and large currents. This paper addresses the analysis of radiated EMI problems associated with DC-DC buck converters and evaluates the effectiveness of solutions that minimize the reverse recovery of the drain-bulk diode of the synchronous switching MOSFET.
Analytical Model For The Rectangular Power-Ground Structure Including Radiation Loss, Ji Chen, Todd H. Hubing, Weimin Shi, R. L. Chen
Analytical Model For The Rectangular Power-Ground Structure Including Radiation Loss, Ji Chen, Todd H. Hubing, Weimin Shi, R. L. Chen
Electrical and Computer Engineering Faculty Research & Creative Works
An accurate analytical model to predict via coupling within rectangular power-return plane structures is developed. Loss mechanisms, including radiation loss, dielectric loss, and conductor loss, are considered in this model. The radiation loss is incorporated into a complex propagating wavenumber as an artificial loss mechanism. The quality factors associated with three loss mechanisms are calculated and compared. The effects of radiation loss on input impedances and reflection coefficients are investigated for both high-dielectric-loss and low-dielectric-loss printed circuit boards. Measurements are performed to validate the effectiveness of this model.