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Design, Development, Test, And Calibration Of The Floating Potential Measurement Unit Sensor Suite, Chad Fish May 2005

Design, Development, Test, And Calibration Of The Floating Potential Measurement Unit Sensor Suite, Chad Fish

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

To provide in-situ plasma diagnostic ability aboard the International Space Station, NASA-Johnson procured the Floating Potential Measurement Unit (FPMU) from Utah State University - Space Dynamics Laboratory in September 2001. The FPMU sensor suite is comprised of a Floating Potential Probe, two sweeping Langmuir Probes, and a Radio Frequency Probe. The FPMU is to be operational for a period of at least three years to cover the major construction phase of the International Space Station. The FPMU will make measurements of ISS floating potential as well as plasma density and temperature, which are the primary environmental factors that effect ISS …

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System And Method For Joint Source-Channel Encoding, With Symbol Decoding And Error Correction, Khalid Sayood, Michael W. Hoffman, Billy D. Pettijohn May 2005

System And Method For Joint Source-Channel Encoding, With Symbol Decoding And Error Correction, Khalid Sayood, Michael W. Hoffman, Billy D. Pettijohn

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed is a system and method for joint source-channel encoding, symbol decoding and error correction, preferably utilizing an arithmetic encoder with operational error detection space; and a combination sequential, and arithmetic, encoded symbol decoder structure.

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Calibration And Results Of The Equis Ii Plasma Impedance Probe (Pip), Seth D. Humphries May 2005

Calibration And Results Of The Equis Ii Plasma Impedance Probe (Pip), Seth D. Humphries

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents the calibration process and analysis results for the two Plasma Impedance Probe (PIP) units that were flown as part of the NASA Equis-I I campaign from the Kwajalein Atoll. The work of calibration that was presented by Krishna Kurra for the PIP on the Floating Potential Measurement Unit (FPMU) is improved and extended herein. The sweeping impedance probe (SIP), the instrument formerly known as plasma sweeping probe (PSP), is an integral part of the PIP. For the SIP, the calibration presented in this work, calibration error less than 5% error is achieved. The calibration is applied to …

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Adaptive Blind Multiuser Detection Over Flat Fast Fading Channels Using Particle Filtering, Yufei Huang, Jianqiu Zhang, Isabel Tienda Luna, Petar M. Djuric, Diego Pablo Ruiz Padillo Apr 2005

Adaptive Blind Multiuser Detection Over Flat Fast Fading Channels Using Particle Filtering, Yufei Huang, Jianqiu Zhang, Isabel Tienda Luna, Petar M. Djuric, Diego Pablo Ruiz Padillo

Electrical & Computer Engineering

We propose a method for blind multiuser detection (MUD) in synchronous systems over flat and fast Rayleigh fading channels. We adopt an autoregressive-moving-average (ARMA) process to model the temporal correlation of the channels. Based on the ARMA process, we propose a novel time-observation state-space model (TOSSM) that describes the dynamics of the addressed multiuser system. The TOSSM allows an MUD with natural blending of low-complexity particle filtering (PF) and mixture Kalman filtering (for channel estimation). We further propose to use a more efficient PF algorithm known as the stochastic -algorithm (SMA), which, although having lower complexity than the generic PF …

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Higher Radix Floating-Point Representations For Fpga-Based Arithmetic, Bryan Christopher Catanzaro Apr 2005

Higher Radix Floating-Point Representations For Fpga-Based Arithmetic, Bryan Christopher Catanzaro

Theses and Dissertations

Field Programmable Gate Arrays (FPGAs) are increasingly being used for high-throughput floating-point computation. It is forecasted that by 2009, FPGAs will provide an order of magnitude greater sustained floating-point throughput than conventional processors. FPGA implementations of floating-point operators have historically been designed to use binary floating-point representations, as do general purpose processors. Binary representations were chosen as the standard over three decades ago because they provide maximal numerical accuracy per bit of floating-point data. However, the unique nature of FPGA-based computation makes numerical accuracy per unit of FPGA resources a more important measure of the usefulness of a given floating-point …

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Estimating The Dynamic Sensitive Cross Section Of An Fpga Design Through Fault Injection, Darrel E. Johnson Apr 2005

Estimating The Dynamic Sensitive Cross Section Of An Fpga Design Through Fault Injection, Darrel E. Johnson

Theses and Dissertations

A fault injection tool has been created to emulate single event upset (SEU) behavior within the configuration memory of an FPGA. This tool is able to rapidly and accurately determine the dynamic sensitive cross section of the configuration memory for a given FPGA design. This tool enables the reliability of FPGA designs and fault tolerance schemes to be quickly and accurately tested. The validity of testing performed with this fault injection tool has been confirmed through radiation testing. A radiation test was conducted at Crocker Nuclear Laboratory using a proton accelerator in order to determine the actual dynamic sensitive cross …

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A Flexible Circuit-Switched Communication Network For Fpga-Based Soc Design, Clint Richard Hilton Apr 2005

A Flexible Circuit-Switched Communication Network For Fpga-Based Soc Design, Clint Richard Hilton

Theses and Dissertations

As FPGA densities continue to improve, single chips are becoming capable of implementing larger and more complex systems. Even today these systems may include several processors working in conjuction with a handful of other standard interfaces or custom modules. Additional system complexity naturally leads to added complexity throughout the different design and implementation stages. Attempting to design such a system while maintaining high performance and within a reasonable time frame is becoming more and more difficult. Architectural design approaches ranging from direct module interconnection to sophisticated bus schemes have been used to build such systems, all with their own trade-offs. …

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Tb3+-Doped K Pb2Br5: Low-Energy Phonon Mid-Infrared Laser Crystal, U. N. Roy, R. H. Hawrami, Y. Cui, S. Morgan, A. Burger, K. C. Mandal, C. C. Noblitt, S. A. Speakman, K. Rademaker, S. A. Payne Apr 2005

Tb3+-Doped K Pb2Br5: Low-Energy Phonon Mid-Infrared Laser Crystal, U. N. Roy, R. H. Hawrami, Y. Cui, S. Morgan, A. Burger, K. C. Mandal, C. C. Noblitt, S. A. Speakman, K. Rademaker, S. A. Payne

Faculty Publications

No abstract provided.

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Reducing Energy In Fpga Multipliers Through Glitch Reduction, Nathaniel Rollins, Michael J. Wirthlin Apr 2005

Reducing Energy In Fpga Multipliers Through Glitch Reduction, Nathaniel Rollins, Michael J. Wirthlin

Faculty Publications

Sponsorship: NASA Earth Science Technology Office (ESTO). While FPGAs provide exibility for performing high-performance DSP functions, they consume a significant amount of power. For arithmetic circuits, a large portion of the dynamic power is wasted on unproductive signal glitches. Pipelining can be used to significantly reduce the unproductive power wasted in signal glitches. This paper presents a methodology for estimating the amount of power consumed by glitches and applies this methodology to non-pipelined, pipelined, and digit-serial multipliers. This glitch estimation is used to evaluate these multipliers using four energy metrics: energy per operation, energy delay, energy throughput, and energy density. …

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Programmable Process Flow Networks, Filip D. Cuckov Apr 2005

Programmable Process Flow Networks, Filip D. Cuckov

Electrical & Computer Engineering Theses & Dissertations

A model that introduces programmability to processes occurring in a cargo terminal simulation through the use of a process language is presented in this thesis. The model provides a means for a straight-forward definition, and redefinition of changing processes, their incorporation in the simulation architecture and efficient execution. The model was built to investigate a solution for transforming the cargo terminal simulation CPortS into a process-oriented simulation without hard-coded processes. The approach taken separates the system into an architecture and a set of processes which utilize and interact with the architecture's resources and infrastructure. The processes that take place within …

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Flexi Radio Base Station (Rbs) Performance Analysis Of Voice And Trafic On Kota 2 Jakarta Barat Base Station Control (Bsc), Mushfar Ferdian, Fitri Yuli Zulkifli Apr 2005

Flexi Radio Base Station (Rbs) Performance Analysis Of Voice And Trafic On Kota 2 Jakarta Barat Base Station Control (Bsc), Mushfar Ferdian, Fitri Yuli Zulkifli

Makara Journal of Technology

Flexi Radio Base Station (RBS) Performance Analysis of Voice and Trafic on Kota 2 Jakarta Barat Base Station Control (BSC). The CDMA 2000 technology uses circuit switch method to handle voice traffic and packet switch method to handle data traffic between the user and RBS (Radio Base Station). These two parameters can be used to measure performance of the network generally, so it is necessary to optimize them. This paper analyze the performance of RBS by measuring its parameters such as set up failure ratio, drop ratio, and occupancy. Furthermore, the traffic increment is calculated too in order to provide …

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User-Controlled, Multimedia-Enhanced Communication Using Prior Knowledge And Experience, S. R. Subramanya, Byung K. Yi Apr 2005

User-Controlled, Multimedia-Enhanced Communication Using Prior Knowledge And Experience, S. R. Subramanya, Byung K. Yi

Electrical and Computer Engineering Faculty Research & Creative Works

This article focuses on enriching the communication, experience between human beings interacting through different kind of devices, including mobile phones and PDAs. the key point is how to effectively exploit multimedia data to enhance the richness of communication without overloading the communication channel. to this end, the system tries to minimize the quantity of information transmitted over the networks and to maximize the usage of locally stored information. the proposed system sends several kinds of data, including continuous video, video clips, still images, and avatars, over the communication channel. the specific data that are sent are based on the parameters …

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Equalization Techniques For Multipath Mitigation In Aeronautical Telemetry, Vladimir Ignacio Paje Mar 2005

Equalization Techniques For Multipath Mitigation In Aeronautical Telemetry, Vladimir Ignacio Paje

Theses and Dissertations

This thesis describes the application of adaptive equalization based on the constant modulus algorithm (CMA) and the decision-feedback minimum mean squared error (DF-MMSE) concept to the two compatible offset QPSK waveforms (FQPSK and SOQPSK-TG) that constitute the ARTM Tier-1 waveforms. An adaptive version of the DF-MMSE equalizer is developed and applied to this application. In the presence of frequency selective multipath interference typically encountered in aeronautical telemetry, both equalization techniques are shown to provide reliable performance for FQPSK and SOQPSK-TG. The performance of both waveforms with the DF-MMSE equalizer is slightly better than that using the CMA equalizer. Implementation trade-offs …

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In-Fiber Optical Devices Based On D-Fiber, Kevin H. Smith Mar 2005

In-Fiber Optical Devices Based On D-Fiber, Kevin H. Smith

Theses and Dissertations

This dissertation presents the fabrication and analysis of in-fiber devices based on elliptical core D-shaped optical fiber. Devices created inside optical fibers are attractive for a variety of reasons including low loss, high efficiency, self-alignment, light weight, multiplexibility, and resistance to electromagnetic interference. This work details how D-fiber can be used as a platform for a variety of devices and describes the creation and performance of two of these devices: an in-fiber polymer waveguide and a surface relief fiber Bragg grating. In D-fiber the core is very close to the flat side of the ‘D’ shape. This proximity allows access …

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Visualization Of Medical Images Over Mobile Wireless Handheld Devices, Min Wu, Khurana Ashish, Nadar Mariappan, Chang Wen Chen Mar 2005

Visualization Of Medical Images Over Mobile Wireless Handheld Devices, Min Wu, Khurana Ashish, Nadar Mariappan, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

With the novel advances in wireless communication and personal mobile handheld devices, a newly emerging technology of medical visualization on mobile handheld is believed to provide advance service for physicians, especially in image-based diagnosis. In this paper, we have implemented a real time easy-to-use 3D volume visualization system on mobile handheld devices. The doctors could use their wireless handheld devices, such as Pocket PC or PDA, interactively access medical image at anytime and anywhere in the hospital building. System architecture, technical problems and solutions are discussed. Experimental results are clear enough to show this system to be practical for clinic …

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A Novel Multiple Description Scalable Coding Scheme For Mobile Wireless Video Transmission, Haifeng Zheng, Lun Yu, Chang Wen Chen Mar 2005

A Novel Multiple Description Scalable Coding Scheme For Mobile Wireless Video Transmission, Haifeng Zheng, Lun Yu, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

We proposed in this paper a novel multiple description scalable coding (MDSC) scheme based on in-band motion compensation temporal filtering (IBMCTF) technique in order to achieve high video coding performance and robust video transmission. The input video sequence is first split into equal-sized groups of frames (GOFs). Within a GOF, each frame is hierarchically decomposed by discrete wavelet transform. Since there is a direct relationship between wavelet coefficients and what they represent in the image content after wavelet decomposition, we are able to reorganize the spatial orientation trees to generate multiple bit-streams and employed SPIHT algorithm to achieve high coding …

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Capacitance-Voltage Study On The Effects Of Low Energy Electron Radiation On Al0.27Ga0.73N/Gan High Electron Mobility Transistor, Thomas D. Jarzen Mar 2005

Capacitance-Voltage Study On The Effects Of Low Energy Electron Radiation On Al0.27Ga0.73N/Gan High Electron Mobility Transistor, Thomas D. Jarzen

Theses and Dissertations

The effects of radiation on semiconductors are extremely important to the Department of Defense since the majority of the defense informational, navigational and communications systems are now satellite-based. Due to the high radiation tolerance of gallium nitride and a plethora of high temperature, high power and high frequency applications, the prospect that gallium nitride based devices will become key components in a multitude of military satellite-based systems is highly probable. AlGaN/GaN HEMTs were irradiated at low temperature (~80 K) by 0.45 – 0.8 MeV electrons up to fluences of 1×1015 e-/cm2. Following irradiation, low temperature capacitance-voltage measurements …

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Using Liquid Crystal Spatial Light Modulators For Closed Loop Tracking And Beam Steering With Phase Holography, Michael J. Perry Mar 2005

Using Liquid Crystal Spatial Light Modulators For Closed Loop Tracking And Beam Steering With Phase Holography, Michael J. Perry

Theses and Dissertations

Optical Phased Array (OPA) technology offers advantages in the reduction of size, weight, and power of optical steering devices. Nematic liquid crystal (LC) spatial light modulators (SLMs) have been studied as a potential candidate for building non-mechanical OPAs. They can steer a laser beam and split the beam into multiple beams. This thesis builds upon the prior research showing each split beam can be individually controlled, including variation in intensity. A closed loop tracking scenario shows the flexibility of the SLM by tracking and stabilizing an incoming beam. Results show that applying a phase grating to the SLM has limitations …

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An Analysis Of Seawinds Simultaneous Wind/Rain Retrieval In Severe Weather Events, Jeffrey R. Allen Mar 2005

An Analysis Of Seawinds Simultaneous Wind/Rain Retrieval In Severe Weather Events, Jeffrey R. Allen

Theses and Dissertations

Scatterometers, such as SeaWinds, can provide wide coverage of ocean surface winds. They estimate near-surface wind vectors by relating measured radar backscatter to a geophysical model function. However, SeaWinds measurements are also sensitive to rain, and conventional wind retrieval degrades in rainy conditions. An algorithm that exploits SeaWinds' sensitivity to both wind and rain has be developed. This algorithm, termed simultaneous wind/rain retrieval, retrieves both wind vectors and rain rates for a given ocean area. Instantaneous results of simultaneous wind/rain retrieval in Hurricane events is analyzed through comparison with the NEXRAD ground-based radar system. This comparison allows validation of retrieved …

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Zero-Knowledge Proofs For Mix-Nets Of Secret Shares And A Version Of Elgamal With Modular Homomorphism, Marius C. Silaghi Mar 2005

Zero-Knowledge Proofs For Mix-Nets Of Secret Shares And A Version Of Elgamal With Modular Homomorphism, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Mix-nets can be used to shuffle vectors of shared secrets. This operation can be an important building block for solving combinatorial problems where constraints are secret to different participants. A main contribution of this paper is to show how participants in the mix-net can provide Zero-Knowledge proofs to convince each other that they do not tamper with the shuffled secrets, and that inverse permutations are correctly applied. The approach is related to the proof of knowing an isomorphism between large graphs. We also make a detailed review and comparison with rationales and analysis of Chaum's and Merritt's mix-nets. Mix-nets offer …

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Chromatic Dispersion Of Thin Film Filters, R. M. Fortenberry, M. A. Scobey, Dennis J. Derickson, L. F. Stokes, P. C. Egerton Mar 2005

Chromatic Dispersion Of Thin Film Filters, R. M. Fortenberry, M. A. Scobey, Dennis J. Derickson, L. F. Stokes, P. C. Egerton

Electrical Engineering

This paper discusses the chromatic dispersion effects of thin film filters used in telecommunications systems. ITU channel, banded architecture, and low dispersion filter results are presented. Design techniques to improve and manage chromatic dispersion in practical network implementations are discussed.

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Optimization Of Automatic Target Recognition With A Reject Option Using Fusion And Correlated Sensor Data, Trevor I. Laine Mar 2005

Optimization Of Automatic Target Recognition With A Reject Option Using Fusion And Correlated Sensor Data, Trevor I. Laine

Theses and Dissertations

This dissertation examines the optimization of automatic target recognition (ATR) systems when a rejection option is included. First, a comprehensive review of the literature inclusive of ATR assessment, fusion, correlated sensor data, and classifier rejection is presented. An optimization framework for the fusion of multiple sensors is then developed. This framework identifies preferred fusion rules and sensors along with rejection and receiver operating characteristic (ROC) curve thresholds without the use of explicit misclassification costs as required by a Bayes' loss function. This optimization framework is the first to integrate both "vertical" warfighter output label analysis and "horizontal" engineering confusion matrix …

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Sea Ice Mapping Method For Seawinds, David G. Long, Hyrum S. Anderson Mar 2005

Sea Ice Mapping Method For Seawinds, David G. Long, Hyrum S. Anderson

Faculty Publications

A sea ice mapping algorithm for SeaWinds is developed that incorporates statistical and spatial a priori information in a modified maximum a posteriori (MAP) framework. Spatial a priori data are incorporated in the loss terms of a Bayes risk formulation. Conditional distributions and priors for sea ice and ocean statistics are represented as empirical histograms that are forced to conform to a set of expected histograms via principal component filtering. Tuning parameters for the algorithm allow adjustments in the algorithm's performance. Results of the algorithm exhibit high correlation with the Remund-Long sea ice mapping algorithm for SeaWinds and the Special …

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An Evaluation Of Wind Turbine Technology At Peterson Afb, Randy C. Combs Mar 2005

An Evaluation Of Wind Turbine Technology At Peterson Afb, Randy C. Combs

Theses and Dissertations

Wind energy technology is a viable source for attaining the emission reduction and renewable energy use goals set forth by the executive office. In accordance with Executive Orders, the Air Force must reduce greenhouse emissions and energy consumption, and expand the use of renewable energy sources within its facilities nation-wide by year 2010. This mandate requires that the Air Force look at alternative electrical production and rely more on such renewable energy resources as wind power. The specific problem addressed by this research is whether on-site wind energy generation can be more economically feasible than the conventional energy consumption at …

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An Analysis Of Information Assurance Relating To The Department Of Defense Radio Frequency Identification (Rfid) Passive Network, Robert G. Giovannetti Mar 2005

An Analysis Of Information Assurance Relating To The Department Of Defense Radio Frequency Identification (Rfid) Passive Network, Robert G. Giovannetti

Theses and Dissertations

The mandates for suppliers to commence Radio Frequency Identification tagging set by Wal-Mart and the Department of Defense is changing this long-time rumored technology into reality. Despite the many conveniences to automate and improve asset tracking this technology offers, consumer groups have obstinately opposed this adoption due to the perceived weaknesses in security and privacy of the network. While the heated debate between consumers and retailers continues, little to no research has addressed the implications of security on the Department of Defense Radio Frequency Identification network. This thesis utilized a historical analysis of Radio Frequency Identification literature to determine whether …

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Daytime Detection Of Space Objects, Alistair D. Funge Mar 2005

Daytime Detection Of Space Objects, Alistair D. Funge

Theses and Dissertations

Space Situational Awareness (SSA) requires repeated object updates for orbit accuracy. Detection of unknown objects is critical. A daytime model was developed that evaluated sun flares and assessed thermal emissions from space objects. Iridium satellites generate predictable sun glints. These were used as a model baseline for daytime detections. Flares and space object thermal emissions were examined for daytime detection. A variety of geometric, material and atmospheric characteristics affected this daytime detection capability. In a photon noise limited mode, simulated Iridium flares were detected. The peak Signal-to- Noise Ratios (SNR) were 6.05e18, 9.63e5, and 1.65e7 for the nighttime, daytime and …

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Design And Simulation Of A Permanent-Magnet Electromagnetic Aircraft Launcher, Dean Patterson, Antonello Monti, Charles W. Brice, Roger A. Dougal, Robert O. Pettus, Srinivas Dhulipala, Dilip Chandra Kovuri, Tiziana Bertoncelli Mar 2005

Design And Simulation Of A Permanent-Magnet Electromagnetic Aircraft Launcher, Dean Patterson, Antonello Monti, Charles W. Brice, Roger A. Dougal, Robert O. Pettus, Srinivas Dhulipala, Dilip Chandra Kovuri, Tiziana Bertoncelli

Faculty Publications

This paper describes the basic design, refinement, and verification using finite-element analysis, and operational simulation using the Virtual Test Bed, of a linear machine for an electromagnetic aircraft launcher, for the aircraft carrier of the future. Choices of basic machine format and procedures for determining basic dimensions are presented. A detailed design for a permanent-magnet version is presented, and wound-field coil and induction machine versions are briefly discussed. The long armature-short field geometry is justified, and in particular the impact of this geometry on the scale of the power electronic drive system is examined.

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Study And Design Of A Capacitively Coupled Polymeric Internal Antenna, Khan M.Z. Shams, Mohammod Ali Mar 2005

Study And Design Of A Capacitively Coupled Polymeric Internal Antenna, Khan M.Z. Shams, Mohammod Ali

Faculty Publications

A capacitively coupled polymeric internal antenna is introduced for Bluetooth or GPS applications. Such an antenna can be easily fabricated on a flexible film substrate and attached to the inside surface of the plastic housing of a portable wireless device; such as a PDA. The proposed antenna saves critical space on the printed circuit board (PCB) and eliminates the need for a vertical contact feed. Thus manufacturing is also simplified and cost is reduced. Practical examples of utilizing such a concept for Bluetooth (2.45 GHz) and GPS (1.575 GHz) applications are provided. The antenna system requires a small coupling plate …

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Study Of Behavior Of Digital Modulations For Beam Steerable Reflectarray Antennas, Fuqin Xiong, Robert R. Romanofsky Mar 2005

Study Of Behavior Of Digital Modulations For Beam Steerable Reflectarray Antennas, Fuqin Xiong, Robert R. Romanofsky

Electrical and Computer Engineering Faculty Publications

This paper investigates the bit error rate (BER) performance of digital modulations in a system with a scanning reflectarray antenna. A reflectarray causes intersymbol interference (ISI) in a digitally modulated signal, its phase shifters' phase errors cause signal distortion, and its phase shifters' phase transient causes beam pattern degradation during direction switching. In this paper, composite signal models of the reflectarray are established for both static and transient states. Due to different feed-to-element distances and the element-to-observation distances, different delays exist in signal components. These delays cause ISI whose effect is analyzed and evaluated. Effects of phase shifters' phase errors …

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The Use Of X-Ray Pulsars For Aiding Gps Satellite Orbit Determination, Dennis W. Woodfork Ii Mar 2005

The Use Of X-Ray Pulsars For Aiding Gps Satellite Orbit Determination, Dennis W. Woodfork Ii

Theses and Dissertations

This research proposes the use of an existing "signal of opportunity" - namely x-ray pulsars - to improve the accuracy and robustness of the GPS satellite and clock estimation algorithm. Improvement in satellite and clock accuracy results in a direct benefit to the user. A simulation has been developed to determine the effects of using x-ray pulsar measurements on the GPS Operational Control Segment. The epoch-specific position, velocity, and clock errors of all GPS satellites in the constellation were estimated using both pseudoranges and time-difference-of-arrival (TDOA) measurements from pulsars. The primary measure of accuracy is a constellation Signal-In-Space Range Error …

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