Ultra-wideband CMOS signal generator using tunable linear superposition

Department of Electrical EngineeringWireless communication frequency bandwidth and center frequency are have been widening for high speed transmission of data. But the frequency bandwidth a transceiver can cover is severely limited. The circuit designed in the paper, called "signal generator", can offer a variety of wireless bandwidths. In this paper, a ultra wideband signal generator, based in 65nm CMOS technology, is designed after proposing and verifying two different types of signal generator design. The first version design of the signal generator is proposed, which is composed of a four-stage LC-ring voltagecontrolled oscillator (VCO) and a frequency synthesis circuit. A new concept of tunable linear superposition is proposed for wideband frequency synthesis and implemented to provide VCO core (1X)/ twofold (2X)/ quadruple (4X) programmable frequency multiplication function. In order to expand frequency coverage further, the LCring VCO adopted the tunable inductors which are composed of switchable bondwire pairs. A ultra-wideband operation from 4.3GHz to 27.4GHz was experimentally verified. The second version design of the signal generator using a reconfigurable phase selection process is proposed, which is proposed and consists of a multi-phase signal generation and a programmable frequency multiplication. This chip is proposed for wideband frequency synthesis and implemented to provide VCO core (1X)/ twofold (2X)/ quadruple (4X) and octuplet (8X) programmable frequency multiplication function. An LC-ring oscillator and a selective rectifying combiner are reconstructed adaptively for various frequency synthesis modes, minimizing their power consumption. A fully-integrated prototype verified to have very wide frequency characteristic from 6.3GHz to 59.4GHz.ope

A toolbox for multi-objective optimisation of low carbon powertrain topologies

Stricter regulations and evolving environmental concerns have been exerting ever-increasing pressure on the automotive industry to produce low carbon vehicles that reduce emissions. As a result, increasing numbers of alternative powertrain architectures have been released into the marketplace to address this need. However, with a myriad of possible alternative powertrain configurations, which is the most appropriate type for a given vehicle class and duty cycle? To that end, comparative analyses of powertrain configurations have been widely carried out in literature; though such analyses only considered limited types of powertrain architectures at a time. Collating the results from these literature often produced findings that were discontinuous, which made it difficult for drawing conclusions when comparing multiple types of powertrains. The aim of this research is to propose a novel methodology that can be used by practitioners to improve the methods for comparative analyses of different types of powertrain architectures. Contrary to what has been done so far, the proposed methodology combines an optimisation algorithm with a Modular Powertrain Structure that facilitates the simultaneous approach to optimising multiple types of powertrain architectures. The contribution to science is two-folds; presenting a methodology to simultaneously select a powertrain architecture and optimise its component sizes for a given cost function, and demonstrating the use of multi-objective optimisation for identifying trade-offs between cost functions by powertrain architecture selection. Based on the results, the sizing of the powertrain components were influenced by the power and energy requirements of the drivecycle, whereas the powertrain architecture selection was mainly driven by the autonomy range requirements, vehicle mass constraints, CO2 emissions, and powertrain costs. For multi-objective optimisation, the creation of a 3-dimentional Pareto front showed multiple solution points for the different powertrain architectures, which was inherent from the ability of the methodology to concurrently evaluate those architectures. A diverging trend was observed on this front with the increase in the autonomy range, driven primarily by variation in powertrain cost per kilometre. Additionally, there appeared to be a trade-off in terms of electric powertrain sizing between CO2 emissions and lowest mass. This was more evident at lower autonomy ranges, where the battery efficiency was a deciding factor for CO2 emissions. The results have demonstrated the contribution of the proposed methodology in the area of multi-objective powertrain architecture optimisation, thus addressing the aims of this research

Experimental development and bond graph dynamic modelling of a brazed plate heat exchanger

This article is devoted to the dynamic study of a brazed plate heat exchanger (BPHE). First, an introduction to the industrial context of the current FUI THERMOFLUIDE project is proposed. A succinct presentation of the heat exchanger technology is proposed. Afterward, a state of the art discussion of BPHE modelling, heat transfer and pressure drop correlations is given. Then a detailed mathematical description of an original dynamic model is presented. The last section deals with a description of the experimental test rig and performed validation tests.FUI Thermodfluid-R

Languages and Tools for Optimization of Large-Scale Systems

Modeling and simulation are established techniques for solving design problems in a wide range of engineering disciplines today. Dedicated computer languages, such as Modelica, and efficient software tools are available. In this thesis, an extension of Modelica, Optimica, targeted at dynamic optimization of Modelica models is proposed. In order to demonstrate the Optimica extension, supporting software has been developed. This includes a modularly extensible Modelica compiler, the JModelica compiler, and an extension that supports also Optimica. A Modelica library for paper machine dryer section modeling, DryLib, has been developed. The classes in the library enable structured and hierarchical modeling of dryer sections at the application user level, while offering extensibility for the expert user. Based on DryLib, a parameter optimization problem, a model reduction problem, and an optimization-based control problem have been formulated and solved. A start-up optimization problem for a plate reactor has been formulated in Optimica, and solved by means of the Optimica compiler. In addition, the robustness properties of the start-up trajectories have been evaluated by means of Monte-Carlo simulation. In many control systems, it is necessary to consider interaction with a user. In this thesis, a manual control scheme for an unstable inverted pendulum system, where the inputs are bounded, is presented. The proposed controller is based on the notion of reachability sets and guarantees semi global stability for all references. An inverted pendulum on a two wheels robot has been developed. A distributed control system, including sensor processing algorithms and a stabilizing control scheme has been implemented on three on-board embedded processors

Experimental Modeling of NOx and PM Generation from Combustion of Various Biodiesel Blends for Urban Transport Buses

Biodiesel has diverse sources of feedstock and the amount and composition of its emissions vary significantly depending on combustion conditions. Results of laboratory and field tests reveal that nitrogen oxides (NOx) and particulate matter (PM) emissions from biodiesel are influenced more by combustion conditions than emissions from regular diesel. Therefore, NOx and PM emissions documented through experiments and modeling studies are the primary focus of this investigation. In addition, a comprehensive analysis of the feedstock-related combustion characteristics and pollutants are investigated. Research findings verify that the oxygen contents, the degree of unsaturation, and the size of the fatty acids in biodiesel are the most important factors that determine the amounts and compositions of NOx and PM emissions

Suspension upgrades for future gravitational wave detectors

To further increase the sensitivity of the aLIGO detectors, upgrading the monolithic fused silica suspension is considered for an upgrade option: a higher stress in the fibre and a longer final stage. One of the challenges for this upgrade will be producing thinner and longer fibres that can hold the test mass safely. Since laser power fluctuations during the fibre fabrication process can produce potentially weak fibres, we present a laser intensity stabilisation technology for fused silica fibre fabrication that was investigated to allow further improvements on fibre production consistency which could be applied to aLIGO upgrades. Fibres fabricated with this new technique showed 30% decreased standard deviation of breaking stress, which indicates that the application of intensity stabilisation technology can improve the statistical strength of fused silica fibres. Combined with a longer polishing duration, the average breaking stress also improved by 9%. As higher stress in the fibre and the longer final stage can improve the detector’s sensitivity, these enhanced technologies will enable us to fabricate thin and robust fibres that can achieve future suspension upgrade requirements

On Organization of Information: Approach and Early Work

In this report we describe an approach for organizing information for presentation and display. "e approach stems from the observation that there is a stepwise progression in the way signals (from the environment and the system under consideration) are extracted and transformed into data, and then analyzed and abstracted to form representations (e.g., indications and icons) on the user interface. In physical environments such as aerospace and process control, many system components and their corresponding data and information are interrelated (e.g., an increase in a chamber s temperature results in an increase in its pressure). "ese interrelationships, when presented clearly, allow users to understand linkages among system components and how they may affect one another. Organization of these interrelationships by means of an orderly structure provides for the so-called "big picture" that pilots, astronauts, and operators strive for

Upgrade Design for Septage Treatment: Pease Tradeport Wastewater Treatment Plant, Portsmouth, New Hampshire

This Major Qualifying Project was completed in conjunction with Stantec to design upgrade options to increase septage treatment capacity at the Pease Wastewater Treatment Plant in Portsmouth, NH. Designs modernized existing technologies and suggested methods to treat glycol waste. Following a site visit, data analysis, design alternative development, and cost estimates, designs were scored in health and safety, environmental and sustainability, economic, and constructability criteria. This project proposes one short-term and one long-term design to resolve existing and future problems