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Electrical and Computer Engineering

Electrical and Computer Engineering Faculty Research & Creative Works

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1999

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Articles 1 - 2 of 2

Full-Text Articles in Engineering

Multimode Solution For The Reflection Properties Of An Open-Ended Rectangular Waveguide Radiating Into A Dielectric Half-Space: The Forward And Inverse Problems, R. Zoughi, Aaron D. Benally, Karl Joseph Bois Dec 1999

Multimode Solution For The Reflection Properties Of An Open-Ended Rectangular Waveguide Radiating Into A Dielectric Half-Space: The Forward And Inverse Problems, R. Zoughi, Aaron D. Benally, Karl Joseph Bois

Electrical and Computer Engineering Faculty Research & Creative Works

Open-ended rectangular waveguides are extensively used in nondestructive dielectric material evaluation. The dielectric properties of an infinite-half space of a material are calculated from the measured reflection properties referenced to the waveguide aperture. This calculation relies on a theoretical and numerical derivation of the reflection coefficient likewise referenced to the waveguide aperture. Most of these derivations assume the dominant mode field distribution across the waveguide aperture. However, when dealing with low permittivity and low loss dielectric materials, there may exist significant errors when calculating the dielectric properties from the measured reflection coefficient. These errors have also shown to be more …


Power Bus Noise Reduction Using Power Islands In Printed Circuit Board Designs, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Y. Ren, Jun Fan, Richard E. Dubroff May 1999

Power Bus Noise Reduction Using Power Islands In Printed Circuit Board Designs, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Y. Ren, Jun Fan, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

Power islands are often used to isolate devices that put noise on a power bus from devices that may be susceptible to power bus noise. At high frequencies however, the effectiveness of these islands depends on the implementation. This paper experimentally investigates the effectiveness of different power island structures at frequencies up to 3 GHz.