Ultra-Wideband (UWB) technologies are at the forefront of wireless communications, offering the possibility to provide extremely high data rate wireless solutions. In addition to high data rate applications, UWB technologies also offer an extremely low cost alternative for many low data rate systems. In this thesis, we describe the design of a CMOS pulse generator for impulse based UWB systems. The structure of our pulse generator is based on the topology of a single tap CMOS power amplifier. By increasing the number of taps on a CMOS power amplifier, it is possible to generate sub-nanosecond pulses with a desired shape. A power saving scheme that significantly reduces the power consumed at low data rates is also described. The versatility of our design lies in the ability to support dynamically varying output power levels and center frequencies. Our pulse generator design is extended to a rectified cosine generator, necessary for a multiband approach. The performance of our pulse generators is estimated through simulation with a target technology of TSMC 0.18 µm CMOS at a supply voltage of 1.8 V. The simulation results indicate that our pulse generator produces high fidelity Gaussian monocycle pulses with a pulse width of approximately 160 ps and a peak output power of more than 10 mW. We believe that our design of a CMOS pulse generator for UWB systems is a feasible option for many applications in which power and cost are most important. / Master of Science

The majority of the UWB radars available on the market today are expensive and often closed forfurther development due to proprietary rights. Therefore it is difficult to fully understand and adaptthe functionality of an available UWB system to fit one’s needs. The consulting-firm Addiva purchasedan UWB radar to be used in a safety system. However, the radar had limitations and the functionalityof it was partly unknown. This master thesis was inspired from this issue to examine the possibilitiesof developing a low-cost UWB radar, with main focus on research of human detection. The systemshould be easy to understand and modify, as well as reporting reliable data from the scanning. Theresults indicate that such a system can be developed. However, further development to the UWB radarneeds to be made in order to have a complete system.

Yes / This paper proposes a formal methodology to analyse bio-systems, in particular synthetic biology systems. An integrative analysis perspective combining different model checking approaches based on different property categories is provided. The methodology is applied to the synthetic pulse generator system and several verification experiments are carried out to demonstrate the use of our approach to formally analyse various aspects of synthetic biology systems. / EPSRC

For this project the main goal was to design, simulate, build and test a DC motor driver. To accomplish this four specific parts had to be design. First a DCDC converter that converts the input signal from an external power supply in a controllable DC output. The second part was a DCDC converter that converts the DC input in a voltage useful for the function generator, the third part is the function generator that provides a signal to the H-Bridge, and the final part is the H-Bridge itself. The goal is to compare the measurement with the simulations to the expectations. What we are interested in is the influence of EMF when the RPM of the motor is zero or close to zero.

Este trabalho descreve o desenvolvimento e a construção de um gerador de pulsos de 8 canais, com interface para controle externo por microcomputador. O gerador possui 16 passos programáveis definindo a largura do pulso entre 200 ns e 10 segundos. Permite também a repetição automática de um intervalo selecionado. O microcomputador tem controle total do gerador de pulsos, incluindo programação de memórias e execução e interrupção de sequências de pulsos. Este gerador foi construído para ser usado em experiências de Ressonância Magnética Nuclear Pulsada, no controle de portas de RF e sistema de detecção / This work describes the development and construction of a 8 channel pulse generator with interface for external microcomputer control. The generator has 16 programmable steps defining pulse widths between 200 nsec and 10 seconds, with 100 nsec resolution. Automatic repeat of a selected step range is also provided. The microcomputer has full control of the pulse generator including programing of memories, execution and interruption of pulse sequences. The generator was built to be used in Pulsed Nuclear Magnetic Resonance experiments to control the high Power RF gate and the detection system

<p>Pulsed power generators are a key component in compact systems for generation of high-power microwaves (HPM). HPM generation by virtual cathode devices such as Vircators put high demands on the source. The rise time and the pulse length of the source voltage are two key issues in the generation of HPM radiation. This thesis describes the construction and tests of several inductive high power pulse generators. The pulse generators were designed with the intent to deliver a pulse with fast rise time and rectangular voltage. Therefore, the pulse generators are all based on discharges of transmission lines. The transmission lines used in the pulse generators are modern high voltage cables normally used in power transmission. All tested pulse generators have step up transformers as intermediate magnetic energy storage. Further, the pulse generators have contributed to the knowledge of compact designs. Closing switches is another important device in pulse generator architectures. In general, high power switching involving large currents and high voltages requires the use of robust switches. The switches used in the pulse generators of this thesis are of gas and liquid type.</p>

This thesis details the design and development of a solid-state, high power modulator for driving plasma ion implantation systems. A plurality of modulators can be stacked in a Marx geometry to allow complete voltage (implantation energy) scalability. Unlike a classic Marx modulator, the design employs actively controlled charging and discharging paths. This allows maximum modulation flexibility and efficiency. A hybrid Marx bank - pulse transformer configuration was commissioned in a 20keV 12A plasma ion implantation system for the purpose of photonics research. <p>The design portion of this work is accompanied by an investigation, extension and discretization of the Lieberman analytical model of plasma ion implantation dynamics. The model predicts final implantation concentrations as well as system operational limits in specific plasma conditions. A new extension to the model accounts for subtle time-of-flight effects on accelerating ions. Agreement between modeled and measured ion currents is good.<p>Finally, a collection of material processing experiments conducted with the plasma ion implantation system since its inauguration in February 2006 is briefly presented. In it, a new silicon-based light emitting diode is introduced.

Pulsed power generators are a key component in compact systems for generation of high-power microwaves (HPM). HPM generation by virtual cathode devices such as Vircators put high demands on the source. The rise time and the pulse length of the source voltage are two key issues in the generation of HPM radiation. This thesis describes the construction and tests of several inductive high power pulse generators. The pulse generators were designed with the intent to deliver a pulse with fast rise time and rectangular voltage. Therefore, the pulse generators are all based on discharges of transmission lines. The transmission lines used in the pulse generators are modern high voltage cables normally used in power transmission. All tested pulse generators have step up transformers as intermediate magnetic energy storage. Further, the pulse generators have contributed to the knowledge of compact designs. Closing switches is another important device in pulse generator architectures. In general, high power switching involving large currents and high voltages requires the use of robust switches. The switches used in the pulse generators of this thesis are of gas and liquid type.

The use of high-voltage pulsed electric fields in biotechnology and medicine has lead to new methods of cancer treatment, gene therapy, drug delivery, and non-thermal inactivation of microorganisms. Regardless of the application, the objective is to open pores in the cell membrane and hence either facilitate the delivery of foreign materials inside the cell or to kill the cell completely. Pulsed power supplies are needed for electroporation, which is the process of applying pulsed electric fields to biological cells to induce a temporary permeability in the cell membrane. The applications of pulsed electric fields are dependent on the output pulse shape and pulse parameters, both of which can be affected by the circuit parameters of the pulsed power supply and the conductivity of the media being treated. <br /><br /> In this research, two Metal Oxide Field Effect Transistor (MOSFET)-based pulsed power supplies that are used for electroporation experiments were designed and built. The first used up to three MOSFETs in parallel to deliver high voltage pulses to highly conductive loads. To produce pulses with higher voltages, a second pulsed power supply using two MOSFETs connected in series was designed and built. The parallel and series MOSFET-based pulsed power supplies are capable of producing controllable square pulses with widths of a few hundred nanoseconds to dc and amplitudes up to 1500 V and 3000 V, respectively. The load in this study is a 1-mm electroporation cuvette filled with a buffer solution that is varied in conductivity from 0. 7 mS/m to 1000 mS/m. The results indicate that by controlling the circuit parameters such as the number of parallel MOSFETs, gate resistance, energy storage capacitance, and the parameters of the MOSFET driver gating pulses, the output pulse parameters can be made almost independent of the load conductivity. <br /><br /> Using the pulsed power supplies designed in this work, an investigation into electroporation-mediated delivery of a plasmid DNA molecule into the pathogenic bacterium <em>E. coli</em> O157:H7, was conducted. It was concluded that increasing the electric field strength and pulse amplitude resulted in an increase in the number of transformants. However, increasing the number of pulses had the effect of reducing the number of transformants. In all of the experiments the number of cells that were inactivated by the exposure to the pulsed electric field was measured.

The use of high-voltage pulsed electric fields in biotechnology and medicine has lead to new methods of cancer treatment, gene therapy, drug delivery, and non-thermal inactivation of microorganisms. Regardless of the application, the objective is to open pores in the cell membrane and hence either facilitate the delivery of foreign materials inside the cell or to kill the cell completely. Pulsed power supplies are needed for electroporation, which is the process of applying pulsed electric fields to biological cells to induce a temporary permeability in the cell membrane. The applications of pulsed electric fields are dependent on the output pulse shape and pulse parameters, both of which can be affected by the circuit parameters of the pulsed power supply and the conductivity of the media being treated. <br /><br /> In this research, two Metal Oxide Field Effect Transistor (MOSFET)-based pulsed power supplies that are used for electroporation experiments were designed and built. The first used up to three MOSFETs in parallel to deliver high voltage pulses to highly conductive loads. To produce pulses with higher voltages, a second pulsed power supply using two MOSFETs connected in series was designed and built. The parallel and series MOSFET-based pulsed power supplies are capable of producing controllable square pulses with widths of a few hundred nanoseconds to dc and amplitudes up to 1500 V and 3000 V, respectively. The load in this study is a 1-mm electroporation cuvette filled with a buffer solution that is varied in conductivity from 0. 7 mS/m to 1000 mS/m. The results indicate that by controlling the circuit parameters such as the number of parallel MOSFETs, gate resistance, energy storage capacitance, and the parameters of the MOSFET driver gating pulses, the output pulse parameters can be made almost independent of the load conductivity. <br /><br /> Using the pulsed power supplies designed in this work, an investigation into electroporation-mediated delivery of a plasmid DNA molecule into the pathogenic bacterium <em>E. coli</em> O157:H7, was conducted. It was concluded that increasing the electric field strength and pulse amplitude resulted in an increase in the number of transformants. However, increasing the number of pulses had the effect of reducing the number of transformants. In all of the experiments the number of cells that were inactivated by the exposure to the pulsed electric field was measured.