Engineering Commons^™

Free-Space Measurements Of Dielectrics And Three-Dimensional Periodic Metamaterials, Clifford E. Kintner

Graduate Theses and Dissertations

This thesis presents the free-space measurements of a periodic metamaterial structure. The metamaterial unit cell consists of two dielectric sheets intersecting at 90 degrees. The dielectric is a polyetherimide-based material 0.001” thick. Each sheet has a copper capacitively-loaded loop (CLL) structure on the front and a cut-wire structure on the back. Foam material is used to support the unit cells. The unit cell repeats 40 times in the x-direction, 58 times in the y-direction and 5 times in the z-direction. The sample measures 12” × 12” × 1” in total. We use a free-space broadband system comprised of a pair …

Dielectric Prism Antenna, Jose Antonio Avila

Open Access Theses & Dissertations

3D printing is revolutionizing the development and manufacturing of devices. Currently multi-material 3D printing, like metals plus dielectrics, is in the early stages and not very accessible. This work set out to develop an all-dielectric antenna that could be 3D printed with current widely accessible 3D printing technologies. The antenna developed is an all-dielectric ultra-thin antenna with a simple geometry. The antenna radiates by using total internal reflection and a circulating mode operating as a leaky whispering gallery mode. We are calling the antenna the dielectric prism antenna because it acts like an optical prism. The dielectric prism antenna was …

Investigating The Possible Sources Of Error Using The Method Of Moments To Solve A Dielectric Scattering Problem, Phillip D. Bishop

Master's Theses (2009 -)

In an electromagnetic scattering problem, an incoming electromagnetic wave interacts with an object. The object is typically located in some medium, such as free space. When this electromagnetic wave becomes incident upon the object, the wave scatters. The goal of this work is to analyze the scattered fields for three different incoming wave types: a plane wave, a monopole line source, and a multipole line source. Each source is incident on an infinitely long circular cylinder of lossless dielectric material. Each source has a unique scattering characteristic.

The volume equivalence principle is used to replace the object geometry with mathematically …

Dielectric And Complex Impedance Properties Of Tetravalent Hafnium (Hf 4+) Integrated Cobalt Ferrite, Luis Javier Sanchez

Open Access Theses & Dissertations

The work presented in this thesis was carried out to understand the effects of tetravalent hafnium (Hf4+) ion on the crystal structure and phase, surface morphology, electrical, dielectric and complex impedance properties of cobalt ferrite (CoFe2O4; CFO). Hafnium incorporated cobalt ferrite, CoFe2-xHfxO4, with x = 0.00, 0.05, 0.075, 0.10, 0.15 and 0.20 were prepared by the standard solid state ceramic synthesis method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterizations were performed to determine the structural properties. Most important aspect of this study is to explore the dielectric and complex impedance properties as a function of variable temperature (T=300-1000 …