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 Title
 INTEGRAL EQUATION DESCRIPTION OF INTEGRATED DIELECTRIC WAVEGUIDES.
 Creator
 Bagby, Jonathan S., Michigan State University
 Abstract/Description

An equivalent polarization integral equation is advanced for use in the analysis of integrated dielectric waveguiding systems. This inhomogeneous Fredholm equation of the second kind in the unknown total waveguide core electric field provides a conceptually exact formulation of the guidance properties of a wide class of practical integrated dielectric waveguides., The integral equation is applied to a generalized axially uniform integrated dielectric waveguiding system. This axial uniformity...
Show moreAn equivalent polarization integral equation is advanced for use in the analysis of integrated dielectric waveguiding systems. This inhomogeneous Fredholm equation of the second kind in the unknown total waveguide core electric field provides a conceptually exact formulation of the guidance properties of a wide class of practical integrated dielectric waveguides., The integral equation is applied to a generalized axially uniform integrated dielectric waveguiding system. This axial uniformity renders the axial integral convolutional in nature, prompting the use of a spatial Fourier transform. This results in an inhomogeneous Fredholm equation for the unknown transformed total core field. Subsequent inversion of the transformed field with the aid of the residue theorem allows identification of two components of the total core field: the surface waves of the guide and the radiation spectrum. These are found in terms of the sources exciting the waveguide, leading to conventional results for excitation of surface waves and a new formulation of the excitation of the radiation spectrum. The behavior of the kernel of the transformed integral equation in the complex plane leads to general criterion for prediction of the important phenomena of guided mode leakage. The problem of line source excitation of the asymmetric slab is addressed, as well as the determination of the eigenvalues of the uniform rectangular strip waveguide., The integral equation is also applied to the interesting problem of plane truncated integrated dielectric waveguides. A modified WeinerHopf technique is used to generate iterative formulae for predicting the radiation and reflection of surface waves incident on the truncation from within the waveguide, as well as the excitation or surface waves due to sources outside of the truncated waveguide. Rapid convergence of the iterative technique is demonstrated through application to the truncated asymmetric slab waveguide., Application of moment method and Neumann series techniques to the integral equation is discussed. Utilization of the integral equation for the analysis of microwave integrated circuits is identified as an important avenue of further study.
Show less  Date Issued
 1984, 1984
 PURL
 http://purl.flvc.org/fcla/dt/40607
 Subject Headings
 Engineering, Electronics and Electrical
 Format
 Document (PDF)
 Title
 Design ofMOSFET ultrawideband low noise amplifiers.
 Creator
 Camacho, Esteban, Bagby, Jonathan S., Florida Atlantic University
 Abstract/Description

UltraWide band (UWB) systems are a new wireless technology capable of transmitting data over a wide spectrum of frequency bands with very low power and high data rates. This technology has the potential to replace almost every cable at home or in an office with a wireless connection. In a UWB receiver, a radio frequency (RF) low noise amplifier (LNA) is one of the most important components. This thesis discusses the entire process involving the design ofUWB low noise amplifiers including a...
Show moreUltraWide band (UWB) systems are a new wireless technology capable of transmitting data over a wide spectrum of frequency bands with very low power and high data rates. This technology has the potential to replace almost every cable at home or in an office with a wireless connection. In a UWB receiver, a radio frequency (RF) low noise amplifier (LNA) is one of the most important components. This thesis discusses the entire process involving the design ofUWB low noise amplifiers including a detailed stage by stage analysis of a computer aided design (CAD) of a MOSFET UWB LNA. Simulation tools and concepts from Level I equations are used in order to design a circuit with a realistic MOS model such as the BSIM3 used in this work. The LNA shows improved power consumption over the designs it is based on while still producing comparable results.
Show less  Date Issued
 2008
 PURL
 http://purl.flvc.org/fau/fd/FA00012510
 Subject Headings
 Electronic circuit design, Integrated circuitsVery large scale integration, Metaloxide semiconductor fieldeffect transistorsDesign, Power transistorsDesign
 Format
 Document (PDF)
 Title
 Theory of and a novel approach to highstability frequency control circuits.
 Creator
 Brunell, David J., Florida Atlantic University, Bagby, Jonathan S.
 Abstract/Description

Portable, wireless devices have become ubiquitous, and everincreasing requirements of functionality and reliability are being placed upon these devices. There is a need to accommodate the oftconflicting requirements of small size, low power consumption, low cost, and extremely accurate control of frequency. To address these RF design requirements, a comprehensive survey of existing frequencycontrol methods is presented, followed by a novel design which accomplishes a high degree of...
Show morePortable, wireless devices have become ubiquitous, and everincreasing requirements of functionality and reliability are being placed upon these devices. There is a need to accommodate the oftconflicting requirements of small size, low power consumption, low cost, and extremely accurate control of frequency. To address these RF design requirements, a comprehensive survey of existing frequencycontrol methods is presented, followed by a novel design which accomplishes a high degree of frequency accuracy through the use of direct digital synthesis and a software seeking algorithm. The proposed design can be implemented pursuant to the requirements of current and future portable wireless devices.
Show less  Date Issued
 2001
 PURL
 http://purl.flvc.org/fcla/dt/12819
 Subject Headings
 Frequency synthesizers, Automatic frequency control, Oscillators, Crystal
 Format
 Document (PDF)
 Title
 Acceleration charge sensitivity in ATquartz resonators.
 Creator
 Anderson, Clifford L. H., Florida Atlantic University, Bagby, Jonathan S.
 Abstract/Description

The behavior of ATquartz resonators subject to acceleration is studied. For an AT strip resonator with cantilever mounting, piezoelectric theory predicts that excitation of the pure lowest frequency flexural mode of vibration generates no charge. However, experiments show electromechanical resonance corresponding to this mode for sinusoidal support motion normal to the plane of the crystal with no applied electric field. An amplifier with a voltage follower first stage senses charge output...
Show moreThe behavior of ATquartz resonators subject to acceleration is studied. For an AT strip resonator with cantilever mounting, piezoelectric theory predicts that excitation of the pure lowest frequency flexural mode of vibration generates no charge. However, experiments show electromechanical resonance corresponding to this mode for sinusoidal support motion normal to the plane of the crystal with no applied electric field. An amplifier with a voltage follower first stage senses charge output from the crystal. Shielding is required to reduce sixty hertz and drive frequency electromagnetic interference. Measurement of resonant frequency and damping factor for the lowest frequency flexural mode is reported for a group of 17.76 MHz oscillator crystals. This mode is responsible for crystal breakage in some portable communications products. Significant variation in sensitivity among crystals was observed. Charge sensitivity of this mode is attributed in part to mechanical coupling to other modes involving torsion and lateral flexure.
Show less  Date Issued
 1995
 PURL
 http://purl.flvc.org/fcla/dt/15126
 Subject Headings
 Quartz crystals, Piezoelectricity, Oscillators, Crystal, Resonators, Acceleration (Mechanics)
 Format
 Document (PDF)
 Title
 Application of MoM: Scattering calculations using condition number.
 Creator
 Zhuang, Zhijun., Florida Atlantic University, Bagby, Jonathan S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

Computational accuracy is widely recognized as a critical issue in applied electromagnetics. Increasing computational power is being applied to solve more complex electromagnetic systems with an emphasis on computational accuracy. The work of this thesis is focused on the implementation of Method of Moments (MoM) to integral equation formulations. The goal of this effort is to use what is known as condition number, and, a heuristic ruleofthumb is applied to investigate the computational...
Show moreComputational accuracy is widely recognized as a critical issue in applied electromagnetics. Increasing computational power is being applied to solve more complex electromagnetic systems with an emphasis on computational accuracy. The work of this thesis is focused on the implementation of Method of Moments (MoM) to integral equation formulations. The goal of this effort is to use what is known as condition number, and, a heuristic ruleofthumb is applied to investigate the computational accuracy of MoM in numerical electromagnetics. Other possible applications of condition number of the MoM matrix are also indicated.
Show less  Date Issued
 1999
 PURL
 http://purl.flvc.org/fcla/dt/15719
 Subject Headings
 Electromagnetism, Moments method (Statistics), Electromagnetic theory, Integral equationsNumerical solutions
 Format
 Document (PDF)
 Title
 Analysis and design of simulated human bodies using the finite difference time domain method.
 Creator
 Napoles, Adrian., Florida Atlantic University, Bagby, Jonathan S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

A threedimensional finite difference time domain analysis of a saline water phantom used in industry for testing bodymounted receivers is presented. Specifically, a saline water phantom known as "Salty" is analyzed. Salty is an acrylic circular cylinder which is filled with a saline solution. The fields at the center of the cylinder and 1 cm external to the surface of the cylinder are obtained with the FDTD method for normally incident TMz and TEz plane wave excitation in free space. The...
Show moreA threedimensional finite difference time domain analysis of a saline water phantom used in industry for testing bodymounted receivers is presented. Specifically, a saline water phantom known as "Salty" is analyzed. Salty is an acrylic circular cylinder which is filled with a saline solution. The fields at the center of the cylinder and 1 cm external to the surface of the cylinder are obtained with the FDTD method for normally incident TMz and TEz plane wave excitation in free space. The results from the FDTD simulation are then compared to the closedform solution, which is obtained by assuming that Salty is infinitely long. A low dielectric constant simulated human body which emulates the performance of Salty is designed using the closedform solution for the near fields of a twolayer cylinder and its performance is verified with the FDTD method.
Show less  Date Issued
 1995
 PURL
 http://purl.flvc.org/fcla/dt/15215
 Subject Headings
 Timedomain analysis, Beepers (Pagers), Electromagnetic wavesScatteringMathematical models
 Format
 Document (PDF)
 Title
 Performance of multicarrier DS CDMA systems in a Nakagami fading channel.
 Creator
 Wang, Jifang., Florida Atlantic University, Bagby, Jonathan S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

The performance of a multicarrier DS CDMA system is evaluated over a Nakagami multipath fading channel. After the spreading process, the data sequence is applied to multiple carrier rather than a single carrier. Each carrier is provided a corralator in the receiver, and the maximalratio combiner is used for the corralator outputs. A bandlimited spreading waveforms are used for selfinterference prevention. Robustness to multipath fading and narrow band interference suppression are achieved...
Show moreThe performance of a multicarrier DS CDMA system is evaluated over a Nakagami multipath fading channel. After the spreading process, the data sequence is applied to multiple carrier rather than a single carrier. Each carrier is provided a corralator in the receiver, and the maximalratio combiner is used for the corralator outputs. A bandlimited spreading waveforms are used for selfinterference prevention. Robustness to multipath fading and narrow band interference suppression are achieved by this type of configuration. A comparison is made with a single carrier system in the presence of interference.
Show less  Date Issued
 1998
 PURL
 http://purl.flvc.org/fcla/dt/15534
 Subject Headings
 Code division multiple access, Wireless communication systems, RadioTransmitters and transmissionFading
 Format
 Document (PDF)
 Title
 Passive Optical Networks with a New Bandwidth Allocation Scheme in Ethernet Passive Optical Networks.
 Creator
 Krijestorac, Sadeta, Bagby, Jonathan S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

With the ever increasing demand for bandwidth intensive applications like videoondemand, interactive television services, highdefmition television (HDTV) and internet telephony, the first mile network, referred to as the last mile network in the earlier stages of its development, has proven to solve the "bottleneck" often experienced between users and the central office. The Ethernet Passive Optical Network (EPON), developed by the IEEE 802.3ah Task Force for Ethernet in the First Mile (EFM...
Show moreWith the ever increasing demand for bandwidth intensive applications like videoondemand, interactive television services, highdefmition television (HDTV) and internet telephony, the first mile network, referred to as the last mile network in the earlier stages of its development, has proven to solve the "bottleneck" often experienced between users and the central office. The Ethernet Passive Optical Network (EPON), developed by the IEEE 802.3ah Task Force for Ethernet in the First Mile (EFM), resolves this bottleneck by providing the user with a fiber optic link to the central office that has many advantages, such as nearly infinite bandwidth, low cost, easy installation and immunity to electromagnetic interference, and a saving of the need for powered components in the signal path from the user to the switch. EPON s have proven to deliver the essential services of voice, video, and data communications reliably, while at the same time providing expected guarantees of the delivery of those services in terms of defined Quality of Service measures (QOS). A continuous theme throughout EPON research has been the study of efficient Dynamic Bandwidth Allocation (DBA) as a key factor in achieving fairness in distributing bandwidth amongst remote network units. This research investigates another factor and its effect on network performance and service delivery: Cycle Demand Proportionality (CDP). By observing the patterns of demand in the network on an individual network unit basis cycle after cycle, deductions regarding load characteristics of some units over others can be made. Decisions can be make about subsequent grant allocations based on this factor and aim to achieve better results in the process. Simulations of EPONs Lmder varying loads incorporating the usc of CDP in conjunction with currently used DBA schemes are made and results are analyzed. A major contribution of this research is a new bandwidth allocation algorithm that gives improved performance in terms of packet delay versus offered load. Performance metrics are compared against two common bandwidth allocation algorithms: Interleaved Polling with Adaptive Cycle Time (IPACT) and Cyclic Polling (CP). Additional results also include improvements in packet loss and throughput. The data that represents traffic for this network has two properties, selfsimilarity and long range dependency. Plotting the autocovariance, autocorrelation, and variance for this traffic, for various aggregation levels demonstrates these properties.
Show less  Date Issued
 2008
 PURL
 http://purl.flvc.org/fau/fd/FA00012571
 Subject Headings
 Ethernet (Local area network system), Optical communications, Computer network protocols, Wavelength divisional multiplexing
 Format
 Document (PDF)
 Title
 Effects of Adaptive Antenna Array Beamforming and Power Management with Antenna Element Selection.
 Creator
 Abazari Aghdam, Sajjad, Bagby, Jonathan S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

This research is the array processing help wireless communication techniques to increase the signal accuracy. This technique has an important part of prevalent applications. The wireless communication system, radar, and sonar. Beamforming is one of methods in array processing that filters signals based on their capture time at each element in an array of antennas spatially. Numerous studies in adaptive array processing have been proposed in the last several decades, which are divided in two...
Show moreThis research is the array processing help wireless communication techniques to increase the signal accuracy. This technique has an important part of prevalent applications. The wireless communication system, radar, and sonar. Beamforming is one of methods in array processing that filters signals based on their capture time at each element in an array of antennas spatially. Numerous studies in adaptive array processing have been proposed in the last several decades, which are divided in two parts. The first one related to nonadaptive beamforming techniques and the next one related to digitally adaptive Beamforming methods. The tradeoff between computational complexity and performance make them different. In this thesis, we concentrate on the expansion of array processing algorithms in both nonadaptive and adaptive ones with application of beamforming in 4G mobile antenna and radar systems. The conventional and generalized sidelobe canceller (GSC) structures beamforming algorithms were employed with a phase array antenna that changed the phase of arrivals in array antenna with common phased array structure antennas. An eightelement uniform linear array (ULA), consisting of dipole antennas, represented as the antenna array. An anechoic chamber measures the operation of beamforming algorithms performance. An extended modified Kaiser weighting function is proposed to make a semiadaptive structure in phased array beamforming. This technique is extended to low complexity functions like hyperbolic cosine and exponential functions. Furthermore, these algorithms are used in GSC beamforming. The sidelobe levels were so lower than other algorithms in conventional beamforming around 10 dB. On the other hand, a uniform linear arrays for smart antenna purposes designed to utilize in implementing and testing the proposed algorithms. In this thesis, performance of smart antenna with rectangular aperture coupled microstrip linear array which experimental investigations carried out for obtaining Xband operation of rectangular microstrip antenna by using aperture coupled feeding technique. Frequency range set at approximately 8.6 to 10.9 GHz, by incorporating frequency range of the antenna resonates for single wideband with an impedance bandwidth of 23%. The enhancement of impedance bandwidth and gain does not affect the nature of broadside radiation characteristics. This thesis describes the design, operation, and realization of the beamforming such as Sidelobe level (SLL) control and null forming array antenna are examined with the prototype. An antenna radiation pattern beam maximum can be simultaneously placed towards the intended user or Signal of interest (SOl), and, ideally nulls can be positioned towards directions of interfering signals or signals not of interest (SNOIs). Finally, we focused on the adaptive digitally algorithms in compact antenna that faces with mutual coupling. The variable stepsize normalized lease mean square (VSNLMS) algorithm is implemented in beamforming. This algorithm utilizes continuous adaptation. The weights are attuned that the final weight vector to the most satisfied result. The gradient vector can be achieved by iterative beamforming algorithm from the available data. This algorithm is compared with LMS, NLMS, VSSNLMS algorithms, it is determined that the VSSNLMS algorithm is better performance to other algorithms. Finally, we introduced novel adaptive IPNNLMS beamformer. This beamformer reaches to faster convergence and lower error floor than the previous adaptive beamformers even at low SNRs in presence of mutual coupling. The experimental results verified the simulation results that the proposed technique has better performance than other algorithms in various situations.
Show less  Date Issued
 2016
 PURL
 http://purl.flvc.org/fau/fd/FA00004789, http://purl.flvc.org/fau/fd/FA00004789
 Subject Headings
 Global system for mobile communications., LongTerm Evolution (Telecommunications), Wireless communication systems., Antennas (Electronics), Antenna arrays., Array processors., Timedomain analysis.
 Format
 Document (PDF)