In mobile communication new applications like wireless internet and mobile video have increased the demand of data-rates. Therefore, new more wideband systems are being implemented. Power amplifiers in the base-stations that simultaneously handle these wideband signals for many terminals (handhelds) need to be highly linear with a considerable band-width. In the past decade LDMOS has been the dominating technology for use in these RF-power amplifiers. In this work LDMOS transistors possible to fabricate in a normal CMOS process have been optimized and analyzed for RF-power applications. Their non-linear behavior has been explored using load-pull measurements. The mechanisms of the non-linear input capacitance have been analyzed using 2D TCAD simulations. The investigation shows that the input capacitance is a large contributor to phase distortion in the transistor. Computational load-pull TCAD methods have been developed for analysis of RF-power devices in high-efficiency operation. Methods have been developed for class-F with harmonic loading and for bias-modulation. Load-pull measurements with drain-bias modulation in a novel measurement setup have also been conducted. The investigation shows that the combination of computational load-pull of physical transistor structures and direct measurement evaluation with modified load-pull is a viable alternative for future design of RF-power devices. Simulations and measurements on the designed LDMOS shows a 10 to 15 % increase in drain efficiency in mid-power range both in simulations and measurements. The computational load-pull method has also been used to investigate the power capability of LDMOS transistors on SOI. This study indicates that either a low-resistivity or high-resistivity substrate should be used in manufacturing of RF-power LDMOS transistors on SOI to achieve optimum efficiency. Based on a proper substrate selection these devices exhibit a 10 % higher drain-efficiency mainly due to lower dissipated power in the devices.

Efficiency and innovative problem solving are contradictory requirements for productdevelopment (PD), and both requirements must be satisfied in companies that strive to remainor to become competitive. Efficiency is strongly related to ”doing things right”, whereasinnovative problem solving and creativity is focused on ”doing the right things”.Engineering design, which is a sub-process within PD, can be viewed as problem solving or adecision-making process. New technologies in computer science and new software tools openthe way to new approaches for the solution of mechanical problems. Product datamanagement (PDM) technology and tools can enable concurrent engineering (CE) bymanaging the formal product data, the relations between the individual data objects, and theirrelation to the PD process. Many engineering activities deal with the relation betweenbehavior and shape. Modern CAD systems are highly productive tools for conceptembodiment and detailing. The finite element (FE) method is a general tool used to study thephysical behavior of objects with arbitrary shapes. Since a modern CAD technology enablesdesign modification and change, it can support the innovative dimension of engineering aswell as the verification of physical properties and behavior. Concepts and detailed solutionshave traditionally been evaluated and verified with physical testing. Numerical modeling andsimulation is in many cases a far more time efficient method than testing to verify theproperties of an artifact. Numerical modeling can also support the innovative dimension ofproblem solving by enabling parameter studies and observations of real and syntheticbehavior. Simulation-driven design is defined as a design process where decisions related tothe behavior and performance of the artifact are significantly supported by computer-basedproduct modeling and simulation.A framework for product modeling, that is based on a modern CAD system with fullyintegrated FE modeling and simulation functionality provides the engineer with tools capableof supporting a number of engineering steps in all life-cycle phases of a product. Such aconceptual framework, that is based on a moderately coupled approach to integratecommercial PDM, CAD, and FE software, is presented. An object model and a supportingmodular modeling methodology are also presented. Two industrial cases are used to illustratethe possibilities and some of the opportunities given by simulation-driven design with thepresented methodology and framework. / QC 20100810

The emergence of new communication standards has put a key challenge for semiconductor industry to develop RF devices that can handle high power and high data rates simultaneously. The RF devices play a key role in the design of power amplifiers (PAs), which is considered as a heart of base-station. From economical point of view, a single wideband RF power module is more desirable rather than multiple narrowband PAs especially for multi-band and multi-mode operation. Therefore, device modeling has now become much more crucial for such applications. In order to reduce the device design cycle time, the researchers also heavily rely on computer aided design (CAD) tools. With improvement in CAD technology the model extraction has become more accurate and device physical structure optimization can be carried out with less number of iterations. LDMOS devices have been dominating in the communication field since last decade and are still widely used for PA design and development. This thesis deals with the optimization of RFLDMOS transistor and its evaluation in different PA classes, such as linear, switching, wideband and multi-band applications. For accurate evaluation of RF-LDMOS transistor parameters, some techniques are also developed in technology CAD (TCAD) using large signal time domain computational load-pull (CLP) methods. Initially the RF-LDMOS is studied in TCAD for the improved RF performance. The physical intrinsic structure of RF-LDMOS is provided by Infenion Technologies AG. A reduced surface field (RESURF) of low-doped drain (LDD) region is considered in detail because it plays an important role in RF-LDMOS devices to obtain high breakdown voltage (BVDS). But on the other hand, it also reduces the RF performance due to high on-resistance (Ron). The excess interface state charges at the RESURF region are introduced to reduce the Ron, which not only increases the dc drain current, but also improve the RF performance in terms of power, gain and efficiency. The important achievement is the enhancement in operating frequency up to 4 GHz. In LDD region, the effect of excess interface charges at the RESURF is also compared with dual implanted-layer of p-type and n-type. The comparison revealed that the former provides 43 % reduction in Ron with BVDS of 70 V, while the later provides 26 % reduction in Ron together with BVDS of 64 - 68 V. In the second part of my research work, computational load pull (CLP) simulation technique is used in TCAD to extract the impedances of RF-LDMOS at different frequencies under large signal operation. Flexible matching is an issue in the design of broadband or multi-band PAs. Optimum impedance of RF-LDMOS is extracted at operating frequencies of 1, 2 and 2.5 GHz in class AB PA. After this, CLP simulation technique is further developed in TCAD to study the non-linear behavior of RF devices. Through modified CLP technique, non-linear effects inside the transistor structure are studied by conventional two-tone RF signals in time domain. This is helpful to detect and understand the phenomena, which can be resolved to improve the device performance. The third order inter-modulation distortion (IMD3) of RF- LDMOS was observed at different power levels. The IMD3 of −22 dBc is obtained at 1-dB compression point (P1-dB), while at 10 dB back off the value increases to −36 dBc. These results were also verified experimentally by fabricating a linear PA. Similarly, CLP technique is developed further for the analysis of RF devices in high efficiency operation by investigating the odd harmonic effects for the design of class-F PA. RF-LDMOS can provide a power added efficiency (PAE) of 81.2 % in class-F PA at 1 GHz in TCAD simulations. The results are verified by design and fabrication of class-F PA using large signal model of the similar device in ADS. In fabrication, a PAE of 76 % is achieved.

Detta examensarbete är den avslutande delen av utbildningen inom maskinteknik på Linnéuniversitetet i Växjö under våren 2013. Arbetet utfördes i samarbete med Rottne Industri AB där skogsmaskiner utvecklas och tillverkas för skogsbruk. Projektet innefattar utveckling av en hjulupphängningskomponent kallad ”hjularm” tillhörande företagets ledande produkt, skördaren H-8. Resultatet slutade i en ny design av hjularmen med hjälp av CAD-modellering, Systems Engineering och FEM-analysering.

A system which allows the computer to capture sketches made by a mechanical designer is described. The system not only recognizes basic features as they are sketched, but it also reasons the spatial relationships between features and builds a high level abstract representation (feature model) of the artifact. The temporal nature of the capture, one feature at a time, serves to form a feature graph that allows for parametric design. The system is composed of three subsystems: a two-dimensional freehand sketching subsystem¹ , a three-dimensional features recognition subsystem, and a spatial reasoning subsystem. The freehand sketching subsystem takes the user's input sketching actions and interprets them as simple, two-dimensional geometric elements, such as line segments, circles, and ellipses, etc. The features recognition subsystem interprets the collection of two-dimensional geometric elements to extract three-dimensional information from them and creates high level abstract representations, features. The spatial reasoning subsystem finds relationships between a new feature and existing features and integrates features to form a single part. The work of the Design Capture System is aimed at capturing sketches of a specific application domain: injected molding plastic parts. Twenty injected molding plastic parts were collected and analyzed to understand the distribution of features. Isometric sketching is selected as the basic constructing method for the system. The processes of freehand sketching and computer-aided drafting were studied to find a better scheme for computer-aided sketching. Conclusions are also presented. ¹The Freehand Sketching Subsystem was accomplished by Roger Fang as a Master project in 1987 at the Department of Mechanical Engineering, Oregon State University, Corvallis, Oregon. / Graduation date: 1991

Anxiety and depression are two disorders frequently diagnosed in adults. Given serious adverse affects such as physical health problems, interpersonal relationship difficulties, and suicide, differentiation in treatment of these often comorbid disorders is a necessity in providing appropriate care. The tripartite model of anxiety and depression (Clark & Watson, 1991) proposes that these disorders are linked by a common trait (Negative Affect) and differentiated by a trait common to depression (lack of Positive Affect) and a trait common to anxiety (Physiological Hyperarousal). The Clinical Assessment of Depression (CAD; Bracken & Howell, 2004), a recently published selfreport narrow-band measure of depression, includes a measure of anxiety related symptoms in its subscale structure. This study explores the validity of the CAD with two established measures: the Beck Depression Inventory – II (Beck, Steer, & Brown, 1996) and the Beck Anxiety Inventory (Beck, & Steer, 1993). College students of 18 to 52 years of age (n = 295) enrolled in undergraduate courses in psychology at a south central Kentucky university provided the study data. These individuals were divided into nonclinical and clinical samples based on self disclosure of a clinical diagnosis to examine differences between groups. Strong positive correlations (above r = .60) between similar CAD scales and total scores on the BAI and BDI-II supported convergent validity for the nonclinical sample. All comparisons supported convergent validity for the clinical sample except the correlation between the BDI-II Total Score and the CAD - Depressed Mood subscale (r = .56). Weak to moderate correlations (r = 0.0 to .59) between dissimilar scales supported divergent validity for all dissimilar comparisons in both samples except the correlation between the BDI-II and the CAD-Anxiety/Worry subscale in the nonclinical sample (r = .66). Hotelling-Williams t-tests were performed to compare correlations of similar and dissimilar constructs. Significant results emerged most comparisons in the nonclinical group support the use of the CAD diagnostic assessment. However, nonsignificant findings for the CAD Anxiety/Worry subscale indicate that this measure lacks the ability to aid diagnose significant levels of anxiety. Only one significant difference between correlations was found for the clinical sample with the CAD – Diminished Interest subscale evidencing significantly stronger correlations with the BDI-II than the BAI. The lack of significant differences for the other CAD scales is discussed relative to the small clinical sample size and the heterogeneity of disorders represented. Results support the use of the CAD as an adequate diagnostic tool for depression with college students. Results did not support the use of the CAD in differential diagnosis of anxiety with college students within the framework of the tripartite model. Implications of the findings are discussed to aid in practice and to suggest further research.

The research described in this thesis concentrates on the development of an integrated assembly process design for aircraft systems. Assembly process design is one of the most important and complicated activities in aircraft manufacturing. Many solutions are suggested in previous research to develop process design method. But gaps are found in assembly process design of aircraft system in following studies. In this research, an integration approach which combined with product development philosophy, design for assembly method and digital assembly technology is proposed to solve the issues in the whole product development lifecycle. Three case studies from different design phase are used to examine the integrated process design method. The research results demonstrate that the proposed digital process design method can be used to develop manufacturing strategies of system assembly in early design phase, and improve the accuracy and operability of assembly instructions according to 3-D assembly process plans in detailed design phase. The product design also benefits from this method in terms of correcting design errors in the concurrent engineering process. A proposed process planning system framework based on lightweight CAD is developed in this research. The customized assembly representation of 3DVIA system illustrates the advantages of lightweight CAD when applying in shop floor.

The main objective of this dissertation is to explore and develop computer-aided-design (CAD) methodologies and optimization techniques for reliability, timing performance, and power consumption of through-silicon-via(TSV)-based and monolithic 3D IC designs. The 3D IC technology is a promising answer to the device scaling and interconnect problems that industry faces today. Yet, since multiple dies are stacked vertically in 3D ICs, new problems arise such as thermal, power delivery, and so on. New physical design methodologies and optimization techniques should be developed to address the problems and exploit the design freedom in 3D ICs. Towards the objective, this dissertation includes four research projects. The first project is on the co-optimization of traditional design metrics and reliability metrics for 3D ICs. It is well known that heat removal and power delivery are two major reliability concerns in 3D ICs. To alleviate thermal problem, two possible solutions have been proposed: thermal-through-silicon-vias (T-TSVs) and micro-fluidic-channel (MFC) based cooling. For power delivery, a complex power distribution network is required to deliver currents reliably to all parts of the 3D IC while suppressing the power supply noise to an acceptable level. However, these thermal and power networks pose major challenges in signal routability and congestion. In this project, a co-optimization methodology for signal, power, and thermal interconnects in 3D ICs is presented. The goal of the proposed approach is to improve signal, thermal, and power noise metrics and to provide fast and accurate design space explorations for early design stages. The second project is a study on 3D IC partition. For a 3D IC, the target circuit needs to be partitioned into multiple parts then mapped onto the dies. The partition style impacts design quality such as footprint, wirelength, timing, and so on. In this project, the design methodologies of 3D ICs with different partition styles are demonstrated. For the LEON3 multi-core microprocessor, three partitioning styles are compared: core-level, block-level, and gate-level. The design methodologies for such partitioning styles and their implications on the physical layout are discussed. Then, to perform timing optimizations for 3D ICs, two timing constraint generation methods are demonstrated that lead to different design quality. The third project is on the buffer insertion for timing optimization of 3D ICs. For high performance 3D ICs, it is crucial to perform thorough timing optimizations. Among timing optimization techniques, buffer insertion is known to be the most effective way. The TSVs have a large parasitic capacitance that increases the signal slew and the delay on the downstream. In this project, a slew-aware buffer insertion algorithm is developed that handles full 3D nets and considers TSV parasitics and slew effects on delay. Compared with the well-known van Ginneken algorithm and a commercial tool, the proposed algorithm finds buffering solutions with lower delay values and acceptable runtime overhead. The last project is on the ultra-high-density logic designs for monolithic 3D ICs. The nano-scale 3D interconnects available in monolithic 3D IC technology enable ultra-high-density device integration at the individual transistor-level. The benefits and challenges of monolithic 3D integration technology for logic designs are investigated. First, a 3D standard cell library for transistor-level monolithic 3D ICs is built and their timing and power behavior are characterized. Then, various interconnect options for monolithic 3D ICs that improve design quality are explored. Next, timing-closed, full-chip GDSII layouts are built and iso-performance power comparisons with 2D IC designs are performed. Important design metrics such as area, wirelength, timing, and power consumption are compared among transistor-level monolithic 3D, gate-level monolithic 3D, TSV-based 3D, and traditional 2D designs.

Las necesidades estéticas actuales en Odontología hacen que el empleo de los composites y las porcelanas sea cada día más frecuente en la práctica diaria. En 1971 se introdujeron de forma experimental y teórica en Odontología las técnicas CAD-CAM (CAD= Computer Aided Design (Diseño asistido por ordenador) / CAM = Computer Aided Manufacturing (Fabricación asistida por ordenador). En 1980, Mörmann y Brandestini empiezan a trabajar en la aplicación clínica del CAD-CAM. De todos los sistemas de trabajo desarrollados hasta la fecha destacaremos el CEREC por ser el que hemos utilizado en nuestro estudio. Realizado por Mörmann y Brandestini en 1980, en 1989 llega a la entonces Escuela de Estomatología de la Universidad de Barcelona con los Profesores Cadafalch y Llombart, desarrollándose nuevas versiones actualizadas y perfeccionadas más adelante. Básicamente el sistema CEREC se compone de una cámara CCD para realizar la impresión óptica, un software que nos permite el diseño de la restauración sobre una pantalla, y una cámara de tallado, en la que podemos distinguir dos motores que mueven un disco y una fresa de diamante de forma independiente.La hipótesis de trabajo que se estableció fue que los tratamientos de acabado en la superficie de la cerámica mecanizada para CAD-CAM mejoran las propiedades mecánicas, y la suma de estos tratamientos aumenta la efectividad de los mismos.En cuanto a los objetivos generales, se pretende demostrar que los materiales cerámicos para CAD-CAM mejoran sus propiedades mecánicas con los tratamientos de acabado a nivel de la superficie externa de los mismos (pulido y/o glaseado).

Detta examensarbete behandlar utformning av inredning i Bombardier Transportations tågmodell Regina. Arbetet omfattar en teknisk rapport med översikt av arbetsgången genom det utförda arbetet och de olika tillämpade tekniker som använts för att nå fram till slutgiltigt resultat. Arbetet omfattar även byggnation av en fullskalemodell vilken finns att beskåda på Mälardalens högskola i Eskilstuna.