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Air Force Institute of Technology

Electromagnetics and Photonics

2005

Articles 1 - 6 of 6

Full-Text Articles in Electrical and Computer Engineering

Protein Impregnated Polymer (Pip) Film Infrared Sensor Using Suspended Microelectromechanical Systems (Mems) Pixels, Tetsuo Kaieda Sep 2005

Protein Impregnated Polymer (Pip) Film Infrared Sensor Using Suspended Microelectromechanical Systems (Mems) Pixels, Tetsuo Kaieda

Theses and Dissertations

The Air Force Research Laboratory Materials and Manufacturing Directorate have developed a novel protein impregnated polymer (PIP) suspension that changes resistivity as a function of absorbed infrared radiation. Due to this property, the PIP is a potential material for use as an uncooled bolometer, or thermal sensor. In this research, a thermally-isolated pixel design, sensor characterization methods, and sensor fabrication and processing steps were developed. To create a microbolometer, the PIP was applied to two prototype micro-electro-mechanical systems (MEMS) surface micro-machined structures. The first is a raised cantilever pixel array that uses residual stress polysilicon and metal film arms to …

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Effects Of Piconet Saturation On A Bluetooth Streaming Audio Channel, Theodore L. Josue Jun 2005

Effects Of Piconet Saturation On A Bluetooth Streaming Audio Channel, Theodore L. Josue

Theses and Dissertations

Bluetooth is a technology for wireless personal area networks (WPAN) that eliminates the need for cables, standardizes interfaces, and can automate many standard office processes such as sending and receiving email, synchronizing schedules, or exchanging business cards. With each workstation creating its own Bluetooth network, called a piconet, different Air Force environments have the potential, in some cases, to create more than 50 overlapping piconets, which significantly increases the potential for inter-piconet interference. This research investigates the effects of inter-piconet interference on a Bluetooth channel, streaming audio, offered at 24, 40, and 64 Kbps. It shows that as the number …

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Electro-Optic Beam Steering Using Domain Engineered Lithium Tantalate, Daren J. Chauvin Mar 2005

Electro-Optic Beam Steering Using Domain Engineered Lithium Tantalate, Daren J. Chauvin

Theses and Dissertations

The operation of a 14-channel five stage electro-optic beam steering device was studied. Beam deflection scanned from 0° to 10.1° was demonstrated. The maximum angle is within 0.3% of design. Many laser systems in operation today implement mechanical beam steering methods that are often expensive in terms of cost, weight and power. They are slow and subject to wear and vibration. A non-inertial beam scanning mechanism, such as one based on the device studied in this research could enhance the performance of these systems. The device studied here is fabricated in LiTaO3 using micro-patterned domain reversal. The 14 channels …

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Computational Model Of One-Dimensional Dielectric Barrier Discharges, Krista G. Marchand Mar 2005

Computational Model Of One-Dimensional Dielectric Barrier Discharges, Krista G. Marchand

Theses and Dissertations

As theory lags experiment for dielectric barrier discharge flow control, two different computational methods are implemented to give further insight into characteristics of the dielectric barrier discharge (DBD). A one-dimensional fluid model of a surface-type dielectric barrier discharge is created using He as the background gas. This simple model, which only considers ionizing collisions and recombination in the electropositive gas, creates an important framework for future studies into the origin of experimentally observed flow-control effects of the DBD. The two methods employed in this study include the semi-implicit sequential algorithm and the fully implicit simultaneous algorithm. The first involves consecutive …

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Timing Of Increasing Electron Counts From Geosynchronous Orbit To Low Earth Orbit, Kirk M. Olson Mar 2005

Timing Of Increasing Electron Counts From Geosynchronous Orbit To Low Earth Orbit, Kirk M. Olson

Theses and Dissertations

Under certain conditions, high energy electron fluxes can increase over short periods of time in the outer radiation belt and diffuse to low altitudes. Sudden increases of high energy electron densities at low altitudes can drastically damage unsuspecting low-earth-orbit satellites. The progression of electron flux increases from a geosynchronous orbit to low-earth orbit during an electron event is somewhat unknown. If the beginning of electron flux increases at low-earth-orbits could be anticipated, warnings could be issued to space system operators allowing time to take proper measures to protect and minimize satellite damage extending satellite lifetimes and space mission operations. The …

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Efficient Electromagnetic Material Characterization Via 2-D Rectangular Waveguide Reduction, Derek R. Dwyer Mar 2005

Efficient Electromagnetic Material Characterization Via 2-D Rectangular Waveguide Reduction, Derek R. Dwyer

Theses and Dissertations

A new, low-frequency, rectangular waveguide-based electromagnetic material characterization technique is developed that will reduce the test sample size in two dimensions realizing up to 75 percent reduction in sample cross-sectional area. To achieve this, custom made, reduced aperture, sample holder flanges were used that reduce the waveguide’s excessive cross-sectional dimensions, resulting in reduced sample fabrication costs. Additionally, MatLab® code was developed to implement the rigorously derived modal-analysis solution that accommodates induced, higher-order transverse electric and transverse magnetic modes and accurately extract the reduced test sample’s constitutive parameters. Experimental results using various test samples are compared to known, full-aperture measurements for …

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