Improvements in process technology and design innovations have resulted in compact and cost effective digital baseband solutions. The radio part, however, has remained a bottleneck in terms of chip area and power consumption as the feature size of analog devices does not directly benefit from scaling. With the addition of yet more standards into emerging products, the requirements of future radios will extend over characteristic performance features into demands of programmable and reconfigurable hardware for radios covering multiple frequency bands. Hence, a guideline in the design of such radios is a large degree of hardware sharing. The thesis investigates the application of sigma-delta modulation to arising multistandard wireless radios. First, it reviews principles in wireless radios, such as selected modulation and access techniques. It also examines several communication standards of personal wireless radios as well as common receiver architectures for their implementation. This is followed by general considerations and background information about sigma-delta modulators. In the third and fourth chapter, implementations to two blocks of a wireless radio receiver system are suggested: An architecture for a frequency synthesizer and an implementation of an analog-to-digital converter. In the first contribution, the thesis develops a novel concept for frequency synthesis that is more suitable for multi-band, multi-standard radio architectures, achieving a large amount of hardware sharing among different wireless standards. As a second pillar, the thesis contributes with the design of a dual-standard sigma-delta modulator for data conversion within a radio receiver. Parts of the work concerning the dual-standard modulator are embodied in a granted swedish patent. / QC 20100830

<p>Measurements of partial discharges are commonly used to diagnose the insulation system in high voltage components. Traditionally a single xed frequency of the applied voltage is used for such measurements as in the Phase Resolved Partial Discharge Analysis (PRPDA) technique. With the Variable Frequency Phase Resolved Partial Discharge Analysis (VF-PRPDA) technique the frequency of the applied voltage is instead variable. This technique provides more information about the condition of the insulation than the PRPDA technique. To extract the extra information a physical understanding of the frequency dependence of partial discharges is necessary.</p><p>In this thesis partial discharges in cylindrical cavities in polycarbonate are measured using the VF-PRPDA technique in the frequency range 10 mHz { 100 Hz. It is studied how the cavity diameter and height inuence the frequency dependence of partial discharges. Insulated cavities are compared with cavities bounded by an electrode. It is shown that from measurements at variable applied frequency it is possible to distinguish between cavities of di erent dimensions and between insulated and metal bounded cavities.</p><p>A two-dimensional eld model of partial discharges in a cylindrical cavity is developed. The sequence of discharges in the cavity is simulated by use of the eld computation program FEMLABR. Discharges are modeled with a voltage and current dependent streamer conductivity and are simulated dynamically to obtain charge and current consistency. It is shown that the frequency dependence of partial discharges is signi - cantly inuenced by the statistical time lag and by the two dielectric time constants related to charge movements on the cavity surface and in the bulk insulation. Simulation results are used to interpret the frequency dependent partial discharge activity in a cylindrical cavity.</p>

<p>The aim with this essay is to find out what the expected changes in the subject physics will lead to for teachers and their pupils in “gymnasiet”. The new fields we have chosen to focus on are electronic structure of condensed matter, nanotechnology and material physics. By studying earlier used curricula and textbooks, we illustrate what teachers may have come into contact with in their teaching careers. The main focus lies on what teachers claim to know about the fields mentioned above and if there is a need for further education. Our results indicate that teachers in general feel insecure about their knowledge of these fields and that further education is desirable. The studied group of teachers also have wishes on how to form possible further education.</p> / <p>Syftet med arbetet är att undersöka vad de väntade förändringarna av fysikämnet kommer att innebära för fysiklärare och elever i den svenska gymnasieskolan. De nya områden vi har valt att fokusera på är den kondenserade materiens elektronstruktur, nanoteknologi samt materialfysik. Genom studier av äldre kursplaner och läroböcker ger vi en bild av vad lärarna kan ha stött på tidigare i deras fysikundervisning. Tyngdpunkten ligger i vad lärarna anser sig kunna inom de ovan nämnda områdena samt om det föreligger något fortbildningsbehov. Våra resultat tyder på att lärarna i allmänhet känner en stor osäkerhet inför dessa nya områden och att fortbildning är önskvärt. De lämnar även önskemål om utformning av en eventuell fortbildning.</p>

The aim with this essay is to find out what the expected changes in the subject physics will lead to for teachers and their pupils in “gymnasiet”. The new fields we have chosen to focus on are electronic structure of condensed matter, nanotechnology and material physics. By studying earlier used curricula and textbooks, we illustrate what teachers may have come into contact with in their teaching careers. The main focus lies on what teachers claim to know about the fields mentioned above and if there is a need for further education. Our results indicate that teachers in general feel insecure about their knowledge of these fields and that further education is desirable. The studied group of teachers also have wishes on how to form possible further education. / Syftet med arbetet är att undersöka vad de väntade förändringarna av fysikämnet kommer att innebära för fysiklärare och elever i den svenska gymnasieskolan. De nya områden vi har valt att fokusera på är den kondenserade materiens elektronstruktur, nanoteknologi samt materialfysik. Genom studier av äldre kursplaner och läroböcker ger vi en bild av vad lärarna kan ha stött på tidigare i deras fysikundervisning. Tyngdpunkten ligger i vad lärarna anser sig kunna inom de ovan nämnda områdena samt om det föreligger något fortbildningsbehov. Våra resultat tyder på att lärarna i allmänhet känner en stor osäkerhet inför dessa nya områden och att fortbildning är önskvärt. De lämnar även önskemål om utformning av en eventuell fortbildning.

Advances in microelectronics technology have enabled us to integrate a complex electronic system (such as a radio) on a single chip or in a single package module, known as system-on-chip (SoC) and system-on-package (SoP) paradigms. This brings not only new opportunities for system integration, but also challenges in design and implementation. One of these challenges is how to achieve an optimum total solution of system integration via chip and package co-design, because there is no tool or design methodology available for such kind of optimization. This thesis focuses on innovative multi-band multi-standard radio front-end design and explores a new design methodology. The motivation of developing this design methodology is to achieve an optimum total solution for radio system implementation via chip and package co-design and co-optimization. The methodology starts from RF packaging and components modeling. Necessary models for both on-chip and off-chip passives are developed. Parasitic effects of packages for radio chips are modeled for particular frequencies. Compared with high-speed digital packaging, RF packaging normally deals with narrow band signals. It is possible to absorb some unwanted parasitics by designing proper port matching networks. In addition, cost-performance trade-offs are performed. In this context, we first developed process and technology based cost models, which include parameters like chip real estate, raw materials, package, test and rework. Impact of process variation on final yield has also been considered in the models by using a statistical analysis approach. Performance of different design options is measured by a special FoM (figure-of-merit). Each type of analog/RF circuit (such as LNA, PA and ADC) has its own dedicated FoM. Through a series of cost-performance trade-offs for different on-chip versus off-chip passives and partitions, an optimum total solution is obtained. Finally, this methodology was demonstrated via a number of design examples for multi-band multi-standard radio front-end. The author has explored the optimum solutions for different circuit architectures and process technologies encompassing parallel, concurrent and digitally programmable multi-band radio frond-end blocks. It is interesting to find that, for complex RF circuits like a multi-band multi-standard radio, moving some passives off-chip will have significant cost-savings. In addition to the above contributions, the author has also developed an MCM-D technology on LCP and glass substrates, based on metal deposition and BCB spin-coating at KTH clean room. The author has also performed some preliminary studies on UWB radio for RFID applications. / QC 20101005

<p>Molecular electronics is envisioned as a possible next step in device miniaturization. It is usually taken to mean the design and manufacturing of electronic devices and applications where organic molecules work as the fundamental functioning unit. It involves the easurement and manipulation of electronic response and transport in molecules attached to conducting leads. Organic molecules have the advantages over conventional solid state electronics of inherent small sizes, endless chemical diversity and ambient temperature low cost manufacturing.</p><p> In this thesis we investigate the switching and conducting properties of photochromic dithienylethene derivatives. Such molecules change their conformation in solution when acted upon by light. Photochromic molecules are attractive candidates for use in molecular electronics because of the switching between different states with different conducting properties. The possibility of optically controlling the conductance of the molecule attached to leads may lead to new device implementations.</p><p> The switching reaction is investigated with potential energy calculations for different values of the reaction coordinate between the closed and the open isomer. The electronic and atomic structure calculations are performed with density functional theory (DFT). It is concluded that there is a large potential energy barrier separating the open and closed isomer and that switching between open and closed forms must involve excited states. </p><p>The conducting properties of the molecule inserted between gold leads is calculated within the Non Equilibrium Green Function theory. The transmission function is calculated for the two isomers with different basis sizes for the gold contacts, as well as the electrostatic potential, for finite applied bias voltages. We conclude that a Au 6s basis give qualitatively the same result as a Au spd basis close to the Fermi level. The transmission coefficient at the Fermi energy is around 10 times larger in the closed molecule compared to the open. This will result in a large difference in conductivity. It is also found that the large difference in conductivity will remain for small applied bias voltages. The results are consistent with earlier work.</p>

Electronic structure calculations constitute a valuable tool to predict the properties of materials. In this study we propose an efficient scheme to study correlated electron systems with essentially only one free parameter, the screening length of the Coulomb potential. A general reformulation of the exchange energy of the correlated electron shell is combined with this method in order to analyze the calculations. The results are interpreted in terms of different polarization channels, due to different multipoles. The method is applied to various actinide compounds, in order to increase the understanding of the complicate behaviour of 5f electrons in these systems. We studied the non-magnetic phase of δ-Pu, where the spin polarization is taken over by a spin-orbit-like term that does not break the time reversal symmetry. We also find that a non-trivial high multipole of the magnetization density, the triakontadipole, constitutes the ordering parameter in the mysterious hidden order phase of the heavy-fermion superconductor URu2Si2. This type of multipolar ordering is also found to play an essential role in the hexagonal-based superconductors UPd2Al3,  UNi2Al3 and UPt3 and in the dioxide insulators UO2, NpO2 and PuO2. The triakontadipole moments are also present in all magnetic actinides we considered, except for Cm. These results led us to formulate a new set of rules for the ground state of a system, that are valid in presence of strong spin-orbit coupling interaction instead of those of Hund; the Katt's rules. Finally, we applied our method to a new class of high-Tc superconductors, the Fe-pnictides, where the Fe 3d electrons are moderately correlated. In these materials we obtain the stabilization of a low spin moment solution, in agreement with experiment, over a large moment solution, due to the gain in exchange energy in the formation of large multipoles of the spin magnetization density. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 705

Many-Body Perturbation Theory is put to test as a method for reliable calculations of the electron-electron interaction in two-dimensional quantum dots. We show that second order correlation gives qualitative agreement with experiments on a level which was not found within the Hartree-Fock description. For weaker confinements, the second order correction is shown to be insufficient and higher order contributions must be taken into account. We demonstrate that all order Many-Body Perturbation Theory in the form of the Coupled Cluster Singles and Doubles method yields very reliable results for confinements close to those estimated from experimental data. The possibility to use very large basis sets is shown to be a major advantage compared to Full Configuration Interaction approaches, especially for more than five confined electrons. Also, the possibility to utilize two-electron correlation in combination with tailor made potentials to achieve useful properties is explored. In the case of a two-dimensional quantum dot molecule we vary the interdot distance, and in the case of a two-dimensional quantum ring we vary the ring radius, in order to alter the spectra. In the latter case we demonstrate that correlation in combination with electromagnetic pulses can be used for the realization of quantum logical gates. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Manuscript.

Thin films provide a remarkable asset, as depositing a thin surface layer can completely alter a material’s characteristics and provide new, inexpensive, and valuable properties. In 2020, a new Chemical Vapour Deposition (CVD) approach was developed at Linköping University, using plasma electrons as reducing agents for the deposition of metallic thin films. To understand the CVD approach, comprehension of the deposition chemistry is crucial. In this thesis, I have performed a theoretical examination of the gas phase and surface chemistry of ferrocene in the recently developed CVD method to form metallic iron thin films, using plasma electrons as reducing agents. Results show that ferrocene anion formation and dissociation are probable in the gas phase, depending on the energy of the plasma electrons. It gets successively easier to dissociate the complex after gaining electrons. The most probable gas phase species leading to film formation was determined as FeCp2-, FeCp, and Cp− under the normal deposition parameters. An electron energy above 220 kJ/mol would suffice for ion formation and dissociation to form FeCp and Cp− fragments. On the surface, ferrocene’s vertical and horizontal adsorption is equally probable, with energies around -72 kJ/mol. Cp, Fe, and FeCp with Fe facing towards the surface interacts stronger with the surface than ferrocene, with adsorption energies of -179, -279 kJ/mol, and -284 kJ/mol. FeCp with Fe facing up from the surface had adsorption energy of -23 kJ/mol. As the surface bonding of Fe and FeCp with Fe facing the surface is stronger than for the other species, this poses a possible way of tuning the CVD method to limit carbon impurities. By providing above 180 kJ/mol energy, for example in the form of heating the substrate, the unwanted species FeCp2, Cp, and FeCp with the ring facing downwards would desorb from the surface, leaving the Fe and FeCp fragments with iron facing towards the surface still adsorbed. This poses a possible way of reducing carbon impurities.

First principle electronic structure theory is used to describe the effect of crystal binding on radiation detectors, electron transport properties, and structural damage induced by intense irradiation. A large database containing general electronic structure results to which data mining algorithms can be applied in the search for new functional materials, a case study is presented for scintillator detector materials. Inelastic cross sections for the generation of secondary electron cascades through impact ionization are derived from the dielectric response of an electron gas and evolved in time with Molecular Dynamics (MD). Qualitative and quantitive estimates are presented for the excitation and relaxation of a sample irradiated with Free Electron Laser pulses. A study is presented in where the structural damage on covalent bonded crystals following intense irradiation is derived from a Tight Binding approach and evolved in time with MD in where the evolution of the sample is derived from GW theory for the quasiparticle spectra and a dedicated Boltzmann transport equation for the impact ionization.