The thesis is focused on the development of a radioamateur short-wave transceiver. The basic functions, features and parameters are described in the introduction. The bandplan and appropriate types of emission are also included in the introductory part. The frequency synthesis module is discussed in the second part of the document. Emphasis is placed on the direct digital synthesis method (DDS) using modern Analog Devices circuits. The proposed DDS module includes a high-speed clock source. The description of an intermediate frequency module with a demodulator is also placed there. The final part in devoted to the design of a transceiver control panel with a graphical display, a keyboard and a rotary encoder. The firmware for an ATmega128 microcontroller is described in detail at the end of the thesis.

Recent studies on growth of telecomm sector depict an ever rising demand for high bandwidth applications such as on-line gaming, high definition television and many more. This demand is coupled with increase in internet connected utilities per house hold - each requiring a portion of bandwidth. The fast development of broadband telecommunication services calls for an upgrade of access infrastructure. This challenge could be met by technologies such as Fiber-To-The-Home/Building (FTTH/B) point-to-multipoint (P2MP) optical access networking. Further, FTTH is also widely regarded as a future proof solution for broadband telecommunication services within scientific and industrial sectors. This has encouraged large amount of research and development throughout the globe to find optimal topologies for FTTH. OFDM based optical access network topology abbreviated as OTONES is an ongoing EU FP 7 project under the PIANO+ framework. The OTONES project addresses the next generation optical access networking on the basis of Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Multiple Access (OFDMA), with special provision for reduced complexity and signal processing aspects of the subscriber side terminals (ONUs). This thesis focuses on the theoretical investigation of OFDM based optical access network topology OTONES. The thesis provides an in depth view of the salient aspects of the topology and formulates the key requirements of OTONES topology. The investigation primarily delves on two important aspects of the topology. First, finding the optimal analog circuitry for the optical network unit (ONU). Second, finding the optimal operation regime for the topology and hence optimizing the system level concept. In this thesis, we show that the requirement of an analog circuitry originates from the need of successive up-conversions in OTONES topology which also produces image spectrum. This image spectrum causes a 3 dB loss in power and spectral efficiency in absence of a proper image rejection circuitry. Thus, we discuss the generic SSB generation methods for efficient image rejection. Novel Bedrosian method based on Bedrosian Theorem is established as a promising method for image rejection. We show that this method is an analog implementation of Hilbert Transform Method and does not involve any approximation. Both generic methods for SSB along with the Novel Bedrosian method are evaluated based on the criterion established for OTONES topology. Finally, optical filtering from the set of generic SSB method is proposed for the downstream path and Novel Bedrosian method is proposed for the upstream path. The tolerance limits for Novel Bedrosian method, are also established for its physical implementation. We further discuss the realistic implementation of various components of the OTONES topology. We also establish the optimal operation regime of the full concurrent topology based on parameters such as input optical power, pilot tone separation and many more. Finally as a key feature of the thesis, we optimize the system level concept of the topology with the use of the proposed Novel Bedrosian Method as the optimal analog circuitry for OTONES topology and provide a region of optimal operation of the topology.

Approved for public release; distribution in unlimited. / This thesis represents a cross Systems Command (NAVSEA/NAVAIR) developed product. The product - the Sunset Supply Base (SSB) system - provides a complete system for addressing the risks and supportability issues involved with Commercial Off the Shelf (COTS) products in Navy combat and support systems. The SSB system was implemented on three Navy combat weapon systems at various phases of the product development life cycle. The main body provides to the Program Management Offices (PMO) and other decision makers, a high level summary of performance expectations. Appendix A - The Sunset Supply Base Architecture - identifies at a high level of abstraction a collaborative architecture providing a roadmap for design and development of the SSB system. Appendix B - The Systems Engineering Development and Implementation (SEDI) plan - is a prescriptive or "How to" manual describing activities that have been used to successfully implement the SSB system. Appendix C - Business Case Analysis (BCA) - presents the data collected as a result of SEDI plan implementation then addresses the business/programmatic attributes showing the viability and value proposition possible through the SSB system. Appendix D - The Marketing Plan for the SSB system - defines methods and practices necessary to establish the SSB system as the alternative of choice. / Chemical Engineer, United States Navy / Systems Engineer, United States Navy

The objective of this thesis is to evaluate the engineering properties of Municipal Solid Waste (MSW) that are necessary in the design of landfills. The engineering properties of MSW such as compressibility, shear strength, stiffness and hydraulic conductivity are crucial in design and construction of landfills. The variation of the engineering properties with time, age and degradation are of paramount importance in the field of landfill engineering. There is a need to address the role of the engineering properties in landfill engineering as it is not apparent how the engineering characteristics vary with time. The thesis presents the results of study of the engineering properties of MSW comprehensively and develops experimental data for design of MSW landfills. The work includes the study of the index properties and the engineering properties of MSW such as compressibility, shear strength, shear modulus and damping ratio and a detailed experimental study of the bioreactor landfill. The components of settlements, variation of shear strength with respect to unit weight and particle size are determined experimentally and analyzed. The dynamic properties such as shear modulus and material damping ratio and its variation with parameters such as unit weight, load, amplitude, degradation and moisture content are studied and analyzed. The normalized shear modulus reduction curve which is used in the seismic analysis of the landfills is developed for MSW based on the experimental results and previous studies. A pilot-scale bioreactor was setup in the laboratory for long term monitoring of the settlement, temperature variation and gas production simultaneously. The parameters of interest viz, pH, BOD, COD, conductivity, alkalinity, methane and carbon-di-oxide were determined. The generated data can be effectively used in the engineered design of landfills. For a better understanding, the present thesis is divided into the following eight chapter Chapter 1 provides a general introduction to the thesis with respect to the importance of engineering properties of MSW and presents the organization of the thesis. Chapter 2 presents a detailed review of literature pertaining to the basic, index and the engineering properties of MSW namely compressibility, shear strength, shear modulus and damping ratio, bioreactor landfill and also the scope of the study. Chapter 3 includes the materials and methods followed in the thesis. Chapter 4 presents the evaluation of compressibility characteristics of MSW including the components of settlement and the settlement model parameters. Chapter 5 presents the determination of the shear strength properties of MSW using direct shear tests and triaxial tests. The variation of the strength with respect to unit weight and the particle size is examined. The results are examined in terms of strength ratio and stiffness ratio and the implications are discussed. Chapter 6 presents the study of the dynamic characters of MSW. The variation of the shear modulus and damping ratio with respect to unit weight, confining pressure, loading frequency, decomposition and moisture content are analyzed. Normalized shear modulus reduction and damping curves are proposed for seismic analysis. Chapter 7 presents the study of the conventional and the bioreactor landfill in a small scale laboratory setup. A large scale experimental setup is fabricated to study the characteristics of a bioreactor landfill and includes the long term monitoring and analysis of temperature, gas, settlement and leachate characteristics periodically. The results of the comprehensive study are presented in this chapter. Chapter 8 summarizes the important conclusions from the various experimental studies reported in this dissertation. Conclusions and the scope of future work are presented. A detailed list of references and the list of publications from the thesis are presented at the end. Appendix A presents the life cycle analysis and life cycle cost analysis of MSW land disposal options. The land disposal options such as open dumps, engineered landfills and bioreactor landfills are analyzed in this study.

Low noise low division 2 GHz RF synthesizer integrated circuits (ICs) are conventionally implemented in some form of HBT process such as SiGe or GaAs. The research in this dissertation differs from convention, with the aim of implementing a synthesizer IC in a more convenient, low-cost Si-based CMOS process. A collection of techniques to push towards the noise and frequency limits of CMOS processes, and possibly other IC processes, is then one of the research outcomes. In a synthesizer low N-divider ratios are important, as high division ratios would amplify in-band phase noise. The design methods deployed as part of this research achieve low division ratios (4 ≤ N ≤ 33) and a high phase comparison frequency (>100 MHz). The synthesizer IC employs a first-order fractional-N topology to achieve increased frequency tuning resolution. The primary N-divider was implemented utilising current mode logic (CML) and the fractional accumulator utilising conventional CMOS. Both a conventional CMOS phase frequency detector (PFD) and a CML PFD were implemented for benchmarking purposes. A custom-built 4.4 GHz synthesizer circuit employing the IC was used to validate the research. In the 4.4 GHz synthesizer circuit, the prototype IC achieved a measured in-band phase noise plateau of L( f ) = -113 dBc/Hz at a 100 kHz frequency offset, which equates to a figure of merit (FOM) of -225 dBc/Hz. The FOM compares well with existing, but expensive, SiGe and GaAs HBT processes. Total IC power dissipation was 710 mW, which is considerably less than commercially available GaAs designs. The complete synthesizer IC was implemented in Austriamicrosystems‟ (AMS) 0.35 μm CMOS process and occupies an area of 3.15 x 2.18 mm2. / Dissertation (MEng)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted

This diploma thesis deals with design and realization of a module for a digital signal procesor, for handheld RFID reader working in UHF band. It utilises a special chip EM4298 for RFID signals processing. Module is controlled by the microcontroller ATmega32L, which communicates with the PC through USB bus. Settings in EM4298 is made by a service program which processes received identifying data obtained from tags. Source codes for microcontroller are created in AVR Studio 4.13 program. Source codes for microcontroller are created in C++ Builder 6.0 program. Further thing is Desing and realization of analog interface and a UHF transceiver for wireless communication with tags. A Webench program was used for the analog interface design, which is freely available on the internet. For verification of parameters of the analog interface it was used PSpice 10.0 program. The UHF transceiver is build-up with a MAX2903 chip (transmitter) and AD8347 (receiver) and transmitting and receiving antennae.

The study, description, design and implementation of selected blocks of multiband shortwave radio station are dealt with in the thesis. Focus is placed on the concept of multiband shortwave radio stations, with an emphasis on high frequency and intermediate frequency circuits. The first chapter is devoted to description of the transceiver block diagram which is designed as superheterodyne. The design of bandpass input filters, intermediate frequency crystal filters and output filters is described. Simulation results and the measured characteristics of the implemented functional blocks are presented. Furthermore, the amplifier circuits which maintain impedance matching of individual blocks are discussed. SSB signal generation in the transmitter part of radio station and final stage power amplification are depicted.