Electronic Devices and Semiconductor Manufacturing Commons^™

Iii-Nitride Transistors With Capacitively Coupled Contacts, Grigory Simin, Z.-J. Yang, A. Koudymov, V. Adivarahan, M. Asif Khan

Faculty Publications

AlGaN∕GaNheterostructure field-effect transistor design using capacitively coupled contacts (C³HFET) is presented. Insulated-gate [C³ metal-oxide-semiconductor HFET(C³MOSHFET)] has also been realized. The capacitively coupled source, gate, and drain of C3 device do not require annealedOhmic contacts and can be fabricated using gate alignment-free technology. For typical AlGaN∕GaNheterostructures, the equivalent contact resistance of C³ transistors is below 0.6Ωmm. In rf-control applications, the C³HFET and especially the C³MOSHFET have much higher operating rf powers as compared to HFETs.C³ design is instrumental for studying the two-dimensional electron gas transport in other wide band gap …

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

Characterization And Quantum Efficiency Validation Of Ingaas Linear Focal Plane Array, Christopher Salenga Garcia

Electrical & Computer Engineering Theses & Dissertations

A 1x1024 InGaAs linear hybrid focal plane array (FPA) with CMOS readout was characterized at room temperature to analyze its electrical and optical properties and to measure its performance parameters.

The most important parameter of an FPA is the gain constant K, which allows conversion of the FPA output measurement unit from digital counts into the number of generated signal electrons. For FPAs with CMOS readout, the commonly used meanvariance method for determining K often underestimates its value. A more reliable method for finding K is the photon transfer technique, which is developed for FPAs with CCD readout. This …

Air Gap Error Compensation For Coaxial Transmission Line Method Of Electromagnetic Material Characterization, Ronald G. Fehlen

Theses and Dissertations

This research analyzes material characterization measurements from 50 Mhz to 3.05 GHz where an axially symmetric air gap exists between the sample material and the inner or outer conductor. Higher order fields are excited by the air gap and are accounted for through modal analysis methods. A root search minimizes the difference between the calculated scattering parameters from the modal method and the experimentally measured scattering parameters. The root is the permittivity and permeability of the material. This method is tested with a non-magnetic material and a heavily loaded magnetic material. An error analysis based on dimension measurement uncertainty is …

Computational Modeling Of The Dielectric Barrier Discharge (Dbd) Device For Aeronautical Applications, Christopher S. Charles

Theses and Dissertations

Dielectric Barrier Discharge (DBD) type devices, when used as plasma actuators, have shown significant promise for use in many aeronautical applications. Experimentally, DBD actuator devices have been shown to induce motion in initially still air, and to cause re-attachment of air flow over a wing surface at a high angle of attack. This thesis explores the numerical simulation of the DBD device in both a lD and 2D environment. Using well established fluid equation techniques, along with the appropriate approximations for the regime under which these devices will be operating, computational results for various conditions and geometries are explored. In …

Wideband Dual Polarized Directional Base Station Antenna, Francisco L. Lerma

Masters

The thesis presents a study of different microwave radiators for wireless applications in the frequency range of 2.2 – 2.5GHz. The performance of microstrip patch antennas and dual polarized dipole antennas were evaluated numerically and experimentally verified. A single microstrip patch and a four- element microstrip array were simulated, fabricated and tested. Simulation was carried out by the finite integration time domain (FITD) method. Polarization diversity is realised using crossed dipoles printed elements. For the crossed dipole elements, two different feed arrangements were studied. Parameters such as return loss, isolation, radiation pattern, gain and bandwidth were measured and found to …

Growth Of Ge Quantum Dots On Si(100)-(2×1) By Pulsed Laser Deposition, M. S. Hegazy, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Self-assembled germanium quantum dots (QDs) were grown on Si(100)-(2×1) by pulsed laser deposition. In situ reflection-high energy electron diffraction (RHEED) and postdeposition atomic force microscopy are used to study the growth of the QDs. Several films of different thicknesses were grown at a substrate temperature of 400 °C using a Q-switched Nd:yttrium aluminum garnet laser (λ= 1064 nm, 40 ns pulse width, 23 J/cm ² fluence, and 10 Hz repetition rate). At low film thicknesses, hut clusters that are faceted by different planes, depending on their height, are observed after the completion of the wetting layer. With increasing film thickness, …