Noise and linearity are the two key concerns in RF transceiver systems. However, the impact of circuit topology and device technology on systems noise and linearity behaviors is poorly understood because of the complexity and diversity involved. There are two general questions that are addressed by the RF device and circuit designers: for a given device technology, how best to optimize the circuit topology; and for a given circuit topology, how best to optimize the device technology to improve the noise and linearity performance. In this dissertation, a systematic noise and linearity calculation method is proposed. This approach offers simple and analytical solutions to optimize the noise and linearity characteristics of integrated circuits. Supported by this approach, the physics of state-of-the-art SiGe HBT technology devices can be decoupled and studied. The corresponding impact on noise and linearity is investigated. New optimization methodologies for noise and linearity at both the device and circuit level are presented. In addition, this thesis demonstrates a technique that accurately extracts ac and noise parameters of devices/circuits in the millimeter-wave range. The extraction technique supports and verifies the device/circuit noise analysis from a measurement standpoint.

This thesis has described a wide tuning range transconductor combining source degeneration, cross-coupled, translinear loop to achieve high linearity. The transconductance tuning range from 220£gs to 1050£gs with 1V input range and the total harmonic distortion is -50dB with 0.6Vpp input voltage. And its application to a fifth-order elliptic low-pass Gm-C filter for the front-end RF circuit is presented. In order to transform the passive element circuit into a Gm-C based filter, a GIC flow method has been used. The proposal Gm-C based filter achieve a with performance a low frequency filtering range from 5Mhz to 10Mhz by transconductance tuning.

The variation of velocity and temperature distribution in arbitrary profile along the centerline in turbulent which encounters non-linearity regular progressive gravity wave and steady uniform flow right in front are investigated analytically and verified by existing experiments. Firstly, the action of periodic waves and current are incorporated into the equation of motion as an external force and applied radiation stress for evaluating the velocity distribution over arbitrary lateral cross section. Based on the momentum exchange after the interaction between turbulent plane jet and oppositive non-linearity wave and uniform flow, the physical characteristics of jet-wave and current are able to be determined theoretically. Secondly, there are critical sections in both velocity and temperature transport processes when the turbulent plane jet influenced by wave and current motion. Fluctuating function will be close to infinity, is the order of wave sharpness; Average velocity for every wave period along the centerline approach to zero, That¡¦s thanks to the momentum of plane jet is extruded by the momentum of wave and current, Beyond the critical section, characteristics of the jet is no longer existing, such phenomena mean that only the wave and current dominating. Velocity and temperature distribution in the zone of flow developed are Gaussian curve, as has been measured in experiment. The momentum extrusion of counter flow in jet is significant in the deep water and small wave; The velocity distribution coefficient is changing with the increasing of counter flow velocity, owing to the entrainment effect, and the potential core will reducing with the increasing of counter flow velocity.

The IEEE 802.11a has become the mainstream protocol used in modern wireless communication system due to its high propagation rate of data (54 Mb/s). To meet high propagation rates, the communication devices used in IEEE 802.11a protocol usually present a high conversion gain and a high linearity (denoted as third order intercept point, IIP3). The IIP3 of conventional up- and down-conversion mixers are only about 0 dBm and -5 dBm, which fail to achieve a high propagation rate of data. This thesis utilizes the TSMC 0.18 £gm CMOS technology to design and fabrication up- and down-conversion mixers with very high linearity for IEEE 802.11a application. The proposed high-linearity up-conversion mixer with 1.01 mm ¡Ñ 0.85 mm chip size and its wide bandwidth (5~6 GHz) is well suited for IEEE 802.11a application. To enhance the linearity and bandwidth, a transconductor stage with gm-boosted structure, a switch stgae with LO-body grounded structure and a load stage with shunt peaking structure are adopted in this research. Under 5.2/5.4/5.8 GHz operating frequencies, the implemented up-conversion mixer demonstrates a high conversion gain of 6.8/7.1/6.3 dB and a high linearity of 8.9/9/13.2 dBm, respectivly. In addition, a moderate consuming power (6.86 mW) of such mixer can be achieved at 1.2 V supply voltage. On the other hand, this thesis also designed and fabricated a high-linearity down-conversion mixer with chip size of 1.02 mm ¡Ñ 0.86 mm and 5.2 GHz center frequency. To improve the linearity and isolation and reduce the high-order noise, a transconductor stage with dual-gate structure and a load stage with RC-tank structure are adopted in this research. According to the EM-simulation resutls, the proposed down-conversion mixer presents a moderate conversion gain of 6 dB and a high linearity of 0.8 dBm. Additionly, a moderate consuming power (6.75 mW) of such mixer can be achieved at 1.8 V supply voltage.

The trade-off between linearity and efficiency is the key limiting factor to wideband power amplifier design. Current wireless research focuses much of its effort on building power amplifiers with the two aforementioned criteria going hand in hand to build an optimal design. This thesis investigates the sources of nonlinearity associated with GaN high electron mobility transistors (HEMT), and their subsequent effects on the linearity metrics of the power amplifier. The investigation began with an analysis of the sources of nonlinearity, and then a design-based approach to mitigate those sources of nonlinearity was developed. This design approach was compared with existing trends in power amplifier design. The device technology used in the design was CREE GaN HEMT (45W and 6W). In this report, a systematic approach to designing a two stage power amplifier is discussed, and analyzed for design of linear and highly efficient power amplifiers for base stations. The designed power amplifier consists of two stages: a driver stage and a power stage. The driver stage aimed to linearize the power stage by using circuit analysis and transistor properties along with providing the necessary gain. The power stage was built to complement the driver stage and to achieve high efficiency for the power amplifier. An inter-stage matching network placed between the two stages allowed for the required matching of impedances; transmission lines in the bias feed controlled the harmonic impedances for optimal performance without disrupting performance at fundamental frequencies. This approach effectively improved, and maintained, high efficiency over 200MHz of bandwidth. The design approach was simulated and fabricated in order to test the feasibility of linear power amplifier operation with the use of digital pre-distortion (DPD). The fabricated prototype achieved about 70% peak efficiency over the bandwidth and maintained linearity above 40dBc adjacent channel leakage ratio (ACLR) and below 3% error vector magnitude (EVM). The measurement results indicated that the need for DPD was eliminated when the power amplifier was operating in back-off at the center frequency (800MHz). This thesis compares the prototyped design with existing multistage designs which use linear drivers. The report provides conclusions derive from measurement results and bandwidth limitations faced throughout the course of the design. Lastly, potential research directions, which may allow researchers to overcome the limitations of this design, are discussed.

Digital-to-Analog Converters (DAC) form the feedback element in sigma-delta modulators. Any non-linearity in the DAC directly degrades the linearity of the modulator at low and medium frequencies. Hence, there is a need for designing highly linear DACs when used in high performance sigma-delta modulators. In this work, the impact of current mismatch on the linearity performance (IM3 and SQNR) of a 4-bit current steering DAC is analyzed. A selective calibration technique is proposed that is aimed at reducing the area occupancy of conventional linearization circuits. A statistical element selection algorithm for linearizing DACs is proposed. Current sources within the required accuracy are selected from a large set of current sources available. As compared with existing calibration techniques, this technique achieves higher accuracy and is more robust to variations in process and temperature. In contrast to existing data weighted averaging techniques, this technique does not degrade SNR performance of the ADC. A 5th order, 500 MS/s, 20 MHz sigma-delta modulator macro-model was used to test the linearity of the DAC.

The main objective of the thesis is to implement different architectures of 16-bit adders such as; Ripple CarryAdder (RCA), Manchester Carry Chain Adder (MCCA) and Kogge Stone Adder (KSA), in 65nm CMOS technology and to study their performance in terms of power, operating frequency and speed at near threshold operating regions. The performance of these adders are evaluated and compared with each other and a final conclusion is made as to which adder structure is more suitable for implementation in a 65nmtechnology for low power applications. Several optimisation techniques are performed for the adders to reduce the delay and power consumption. Propagation delay is the most critical or essential parameter to be considered, hence, to minimise the delay of the adder, a technique called sizing and ordering are required for the transistors. The purpose of the thesis is to make a fair comparison among adders over several metrics which include linearity, delay and power. Simulation results of MCCA achieved a greater significant performance upon or over RCA and KSA, and proved it is the best suitable adder for low power applications.

Linear problems are possibly the kindest problems in physics and mathematics. Given sufficient information, the linear equations describing such problems are intrinsically solvable. The solution can be written as a vector having undergone a linear transformation in a vector space; extracting the solution is simply a matter of inverting the transformation. In an ideal optical system, the problem of extracting the object under investigation would be well defined, and the solution trivial to implement. However, real optical systems are all aberrated in some way, and these aberrations obfuscate the information, scrambling it and rendering it inextricable. The process of detangling the object from the aberrated system is no longer a trivial problem or even a uniquely solvable one, and represents one of the great challenges in optics today. This thesis provides a review of the theory behind optical microscopy in the presence of absent information, an architecture for the modern physical and computational methods used to solve the linear inversion problem, and three distinct application spaces of relevance. I hope you find it useful.

abstract: As the photovoltaic (PV) power plants age in the field, the PV modules degrade and generate visible and invisible defects. A defect and statistical degradation rate analysis of photovoltaic (PV) power plants is presented in two-part thesis. The first part of the thesis deals with the defect analysis and the second part of the thesis deals with the statistical degradation rate analysis. In the first part, a detailed analysis on the performance or financial risk related to each defect found in multiple PV power plants across various climatic regions of the USA is presented by assigning a risk priority number (RPN). The RPN for all the defects in each PV plant is determined based on two databases: degradation rate database; defect rate database. In this analysis it is determined that the RPN for each plant is dictated by the technology type (crystalline silicon or thin-film), climate and age. The PV modules aging between 3 and 19 years in four different climates of hot-dry, hot-humid, cold-dry and temperate are investigated in this study. In the second part, a statistical degradation analysis is performed to determine if the degradation rates are linear or not in the power plants exposed in a hot-dry climate for the crystalline silicon technologies. This linearity degradation analysis is performed using the data obtained through two methods: current-voltage method; metered kWh method. For the current-voltage method, the annual power degradation data of hundreds of individual modules in six crystalline silicon power plants of different ages is used. For the metered kWh method, a residual plot analysis using Winters’ statistical method is performed for two crystalline silicon plants of different ages. The metered kWh data typically consists of the signal and noise components. Smoothers remove the noise component from the data by taking the average of the current and the previous observations. Once this is done, a residual plot analysis of the error component is performed to determine the noise was successfully separated from the data by proving the noise is random. / Dissertation/Thesis / Masters Thesis Engineering 2016

L'analyse de sensibilité globale a un rôle clé à jouer dans la conception et la paramétrisation des modèles structure-fonction de la croissance des plantes (FSPM). Ceux-ci combinent la description du développement structurel des plantes (organogénèse et géométrie) et de leur croissance fonctionnelle (accumulation de biomasse et allocation). Les modèles de ce type décrivent généralement de nombreux processus en interaction, comptent un grand nombre de paramètres et leur coût de calcul peut être important. L'objectif de cette thèse est de développer une méthodologie appropriée pour l'analyse de sensibilité des modèles structure-fonction des plantes et d'étudier comment l'analyse de sensibilité peut aider à la conception et la paramétrisation de ces modèles, ainsi qu'à l'analyse et la compréhension des processus biologiques en jeu. Notre contribution peut être vue en deux parties : du point de vue méthodologique Et du point de vue de l'application des méthodes aux modèles. D'un point de vue méthodologique, nous avons tout d'abord amélioré les performances de la méthode de Sobol pour le calcul des indices de sensibilité en termes d'efficacité de calcul, avec un meilleur contrôle de l'erreur d'estimation par les simulations de Monte Carlo. Nous avons _également conçu une stratégie d'analyse adaptée aux systèmes biophysiques complexes. Du point de vue applicatif, nous avons implémenté notre stratégie pour 3 FSPMs avec des niveaux de complexité différents, et nous avons analysé les résultats selon différents aspects, paramétrisation et diagnostic de modèles. / Global sensitivity analysis has a key role to play in the design and parameterization of functional-structural plant growth models (FSPM) which combine the description of plant structural development (organogenesis and geometry) and functional growth (biomass accumulation and allocation). Models of this type generally describe many interacting processes, count a large number of parameters, and their computational cost can be important. The general objective of this thesis is to develop a proper methodology for the sensitivity analysis of functional structural plant models and to investigate how sensitivity analysis can help for the design and parameterization of such models as well as providing insights for the understanding of underlying biological processes. Our contribution can be summarized in two parts: from the methodology point of view, we first improved the performance of the existing Sobol's method to compute sensitivity indices in terms of computational efficiency, with a better control of the estimation error for Monte Carlo simulation, and we also designed a proper strategy of analysis for complex biophysical systems; from the application point of view, we implemented our strategy for 3 FSPMs with different levels of complexity, and analyzed the results from different perspectives (model parameterization, model diagnosis).