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Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

1999

Missouri University of Science and Technology

Mathematical Models

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Slot And Aperture Coupling For Airflow Aperture Arrays In Shielding Enclosure Designs, Min Li, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren Aug 1999

Slot And Aperture Coupling For Airflow Aperture Arrays In Shielding Enclosure Designs, Min Li, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The coupling between apertures or slots in airflow arrays is investigated numerically by means of the method of moments (MoM). Application to shielding enclosure design is of particular interest. Justification for a previously extracted simple empirical design approach for the relation between the number N and size a of apertures, and the shielding effectiveness ∼Na3 for an airflow aperture array is given. The coupling between slots is also investigated. The application limit of the empirical design approach is demonstrated.


Rf Isolation Using Power Islands In Dc Power Bus Design, Jun Fan, Yong Ren, Juan Chen, David M. Hockanson, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff Aug 1999

Rf Isolation Using Power Islands In Dc Power Bus Design, Jun Fan, Yong Ren, Juan Chen, David M. Hockanson, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

Power island structures are often employed for minimizing the propagation of high-frequency noise on DC power buses. The rationale is based on introducing a series impedance in the power plane to provide isolation of a noise source from the rest of the PCB design. The power island concept is investigated herein experimentally, to determine its noise mitigation attributes and limitations. A modeling approach that is suitable for arbitrary PCB island geometries including lumped SMT decoupling capacitors is also presented. The modeling and measurements indicate that island structures can achieve some degree of isolation under certain conditions.


A Blind Deconvolution Approach For Resolution Enhancement Of Near-Field Microwave Images, Ali Mohammad-Djafari, Nasser N. Qaddoumi, R. Zoughi Jul 1999

A Blind Deconvolution Approach For Resolution Enhancement Of Near-Field Microwave Images, Ali Mohammad-Djafari, Nasser N. Qaddoumi, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper we propose a blind deconvolution method to enhance the resolution of images obtained by near-field microwave nondestructive techniques using an open ended rectangular waveguide probe. In fact, we model such images to be the result of a convolution of the real input images with a point spread function (PSF). This PSF depends mainly on the dimensions of the waveguide, the operating frequency, the nature of the object under test and standoff distance between the waveguide and the object. Unfortunately, it is very difficult to model this PSF from the physical data. For this reason, we consider the …