<p>Minskad effektförbrukning har blivit mer och mer intressant i takt med att fler produkter blir mobila. I artikeln Parallel Implementation of Linear Feedback Shift Registers for Low Power Applications, beskriver Menahem Lowy en metod för att konstruera slumptalsgeneratorer. Dessa är tänkta att vara effektsnålare än en vanlig enkel slumptalsgenerator, med återkopplat skiftregister. I det här examensarbetet har sex slumptalsgeneratorer konstruerats i VHDL. Två är baserade på Lowy’s metod och två är parallella varianter av dessa. Dessutom har en seriell slumptalsgenerator med återkopplat skiftregister och en parallell variant konstruerats som jämförelse. Dessa slumptalsgeneratorer har simulerats med avseende på effektförbrukningen. Detvisar sig att den bästa slumptalsgeneratorn, räknat i effekt per bit, är den parallella varianten av slumptalsgeneratorn med återkopplat skiftregister.</p> / <p>Reduced power consumption have become more and more of interest as more products are becoming mobile. In the article Implementation of Linear Feedback Shift Registers for Low Power Applications, Menahem Lowy describes a method of designing randombit-generators. In this project, six random bit-generators have been designed in VHDL. Two of these are based on Lowy’s method, and two are parallel variants of these. In addition, a serial feedback shift register and a parallel variant of it, have been designed for comparison. These randombit- generators have then been simulated with respect to the power consumption. It turnes out that the best randombit-generator, considering the effect per bit, is the parallel variant of the feedback shift register.</p>

<p>Detta examensarbete syftar till att skapa en modulgenerator som automatiskt genererar matchade motstånd. Med hjälp av sådana motstånd kan prestandan i integrerade kretsar förbättras. </p><p>Modulgeneratorn som konstruerats klarar av att generera två eller flera matchade motstånd. Programmet skapar med hjälp av indata från konstruktören en färdig layout som kan användas somett byggblock i integrerade kretsar. </p><p>Examensarbetet har slutförts och programmet har använts för att generera matchade motstånd till två större layouter vid institutionen för Elektroniksystem.</p> / <p>The aim of this thesis is to create a program that automatically generates matched resistors. By using such resistors the performance of integrated circuits can be improved. </p><p>The program can generate two or more matched resistors. With a set of input parameters the user is able to generate a customized matched resistor. </p><p>The project has been completed and the program has been used to generate matched resistors for two bigger layouts at the department of Electrical Engineering.</p>

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Jenn, David C. Second Reader: Pace, Phillip E. "December 2009." Description based on title screen as viewed on January 28, 2010. Author(s) subject terms: Direct conversion, homodyne, IQ mismatch, DC offsets, IQ circle, phase error, modulator, demodulator calibration, LabVIEW, Directional Finding (DF), digital beamforming, Robust Symmetrical Number System (RSNS). Includes bibliographical references (p. 73-75). Also available in print.

A near-infrared spectrometer incorporating solid-state design applicable for industrial quantitative/qualitative process monitoring analysis is presented. The solid-state near-infrared spectrometer provides inherent wavelength stability necessary for long term calibration accuracy. The spectrometer consists of a 24 volt, 10 watt quartz-halogen-tungsten regulated source with optical feedback. Wavelength dispersion was accomplished using a 50 μm entrance slit, f/4, 0.25 meter spectrograph equipped with astigmatism correcting toroidal mirrors and a 300 gr/mm plane reflectance ruled grating blazed for 2000 nm peak efficiency. A 1024 element backside- illuminated Schottky-barrier PtSi photodiode array detector with wavelength response from 900-5000 nm and peak quantum efficiency of 8% at 1100 nm was operated using cryogenic cooling to reduce dark response. A readout rate of 31.25 kHz produced 41 msec integration time per array read. The readout was digitized to 16 bit resolution for subsequent data storage. This system demonstrated 1.5 nm spectral bandpass, 3 orders linear dynamic range and typical baseline rms noise level of 10⁻⁴ a.u. Using this system, quantitative/qualitative chemical analyses were performed focusing on industrial analytical chemical applications. Simultaneous quantitative multcomponent xylene isomer mixtures analysis was achieved using the solid-state near-infrared spectrometer coupled with partial least squares regression multivariate data treatment. The results demonstrate an absolute accuracy of ± 0.05, ±0.12 and ±0.09% w/v for o-, m- and p-xylene isomers respectively. In a separate chemical study, qualitative classification analysis of specially denatured alcohol mixtures was successfully performed on 53 validation samples using 35 reference samples belonging to 12 classes. The validation set included mixture sample types used for model calibration as well as others composed of compounds not used for model calibration. The multivariate cluster classification method using principal components was employed to correctly classify 100% of the validations samples analyzed. The solid-state near-infrared spectrometer was also applied for direct reaction monitoring of the O-H overtone absorption band at 1411 nm for the reaction between triisopropyl-chlorosilane and methanol. The results illustrated the utility of near-infrared functional group monitoring of reactions at relatively high concentrations for information elucidation concerning reaction initiation and completion.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2008. / Dr. David Gerlach, Committee Member ; Dr. Samuel Graham, Committee Member ; Dr. Minami Yoda, Committee Member ; Dr. Yogendra Joshi, Committee Chair.

A multiple-antenna-multiple-equalizer (MAME) system is proposed for overcoming cochannel interference (CCI) in code-division multiple access (CDMA) indoor wireless systems. The main advantage of the MAME system is the enhanced interference suppression capability as compared with many existing approaches. Thus, the use of the MAME system can lead to an increase in the capacity of the CDMA system. In the MAME system, a fractionally-spaced equalizer (FSE) is used to process the signal at each antenna. The number of antennas or the tap spacing of the FSEs is not fixed and inherent flexibility is available to the designer. In particular, CDMA indoor wireless systems are best suited to use the interference suppression capabilities of the MAME system. It is shown that spectral correlation present in user signals is the reason for the interference suppression capability of the MAME system. Moreover, the MAME system is interpreted as a dual-domain diversity combiner. Spatial and bandwidth-domain diversity are used and the relative importance of the diversity domains is discussed. These discussions offer new insights into the interference suppression capabilities of the MAME system and give a clear picture of its workings. Extensive simulation results are presented to illustrate the performance of the MAME system under various conditions. Optimal or minimum mean-squared error (MMSE) results are first presented to illustrate the superior interference suppression performance. The effects of the number of antennas, tap spacing, receive filtering, spectral correlation, diversity domains, and near-far conditions on performance are examined and results obtained support the arguments presented earlier in the thesis. The FSEs in the MAME system are implemented as adaptive filters and the mean-squared- error (MSE) performance is investigated. A quasi-Newton (QN) algorithm is recommended over other adaptive filtering algorithms because of ill-conditioning of the autocorrelation matrix in the MAME system. Simulation results confirm the superior convergence performance of the QN algorithm. Decision-directed equalization is also investigated and bit-error rate (BER) results presented illustrate that the gains in the MMSE performance will most likely translate into gains in BER performance. The BER performance in near-far and birth of interferers conditions illustrate that the MAME system is a promising solution to counter these problems. The thesis concludes with an indoor wireless strategy based on the MAME system which offers the following advantages: 1. More users than the processing gain of the CDMA system can share the same bandwidth. 2. No information about code sequences is needed at the receiver. 3. Simple code sequence allocation schemes can be used at the transmitter. 4. Variable numbers of users can be accommodated. 5. Simple power control and error-correction coding schemes can be used. / Graduate

Compliant electronics are an emerging class of electronics which offer physical flexibility in their structure. Such mechanical flexibility opens up opportunities for wide ranging applications. Nonetheless, compliant electronics which can be functional in unusual environments are yet to be explored. Unusual environment can constitute a harsh environment where temperature and/or pressure is much higher or lower than the usual room temperature and/or pressure. Unusual environment can be an aquatic environment, such as ocean/sea/river/pond, industrial processing related liquid and bodily fluid environment, external or internal for implantable electronics. Finally, unusual environment can also be conditions when extreme physical deformation is anomalously applied to compliant electronics in order to understand their performance and reliability under such extraordinary mechanical deformations. Therefore, in this thesis, three different aspects of compliant electronics are thoroughly studied, addressing challenges of material selection/optimization for unusual environment applications, focusing on electrical performance and mechanical flexible behavior. In the first part, performance of silicon-based high-performance complementary metal oxide semiconductor (CMOS) devices are studied under severe mechanical deformation. Next, a high-volume manufacturing compatible solution is offered to reduce the usage of toxic chemicals in semiconductor device fabrication. To accomplish this, Germanium Dioxide (GeO2) is simultaneously used as transient material and dielectric layer to realize a dissolvable/bioresorbable transient electronic system which can be potentially used for implantable electronics. Finally, wide bandgap semiconductor Gallium Nitride is studied to understand its mechanical flexibility under high temperature conditions. In summary, this research contributes to the advancement of material selection, optimization and process development towards achieving compliant and transient devices for novel applications in unusual environments.

The future of microprocessors is unknown. Over the past 40 years, their historical trend has been for adopting smaller and more powerful designs that drive the world that we live in today. The state of the microprocessor business today faces a crossroad, wishing to continue on the historical trend of doubling the number of transistors on a chip every 18 months (Moore’s Law) but also facing the realistic task of needing to power these sophisticated devices. With the low voltages and high currents that are required for these microprocessors to operate, it poses a difficult task for the future designers of the voltage regulators that are used to power these microprocessors. The technique that has been widely adopted as the preferred method to power these devices is called a multiphase buck converter, or multiphase voltage regulator. This thesis is a continuation of and is aimed to improve previous work done by two former Cal Poly students, Kay Ohn and Ian Waters. A new design that uses an interleaving control scheme, careful component selection, an input LC filter, and a reduction in board size seeks to improve the efficiency, input current noise, and increase the current density of the original design. Research was first conducted to determine how to best make such improvements. The design phase ensued, which used design calculations and simulations to test if the proposed multiphase topology was plausible. Once the theory was fully proven, a real hardware circuit was created and tested to confirm the results. The results yield a multiphase design with improved input noise filtering, greater efficiency, more equal current sharing, and higher current density as compared to previous topologies in this field. Parameters such as output voltage ripple, load and line regulation, and transient response remained excellent, as they were with the previous work.

<p>Color-shift keying (CSK) is a visible light communication (VLC) intensity modulation scheme, outlined in IEEE 802.15.7, that transmits data imperceptibly through the variation of the light color emitted by a red, green, and blue (RGB) light emitting diode (LED). Unlike other intensity modulation schemes, CSK guarantees that the intensity of the luminary will not fluctuate, thus limiting potential human health complications related to flickering light.</p> <p>In this work, a rigorous design framework for CSK constellations is presented. The benefits of the frame work are that it can optimize constellations while accounting for cross talk between the color communication channels formed by the colored LEDs. Unlike previous works, the method applies the study of colorimetry to optimize higher order CSK constellations such that the luminary functions with a desired operating color, allowing constellations to be designed to meet lighting industry quality metrics.</p> <p>This work concludes with the implementation of a CSK communication channel for the purposes of measuring the symbol error rate (SER) versus signal to noise ratio (SNR) of CSK constellations. It is demonstrated that the optimized constellations can achieve equal performance to the standardized constellations, outlined in Section 12 of IEEE 802.15.7, while only requiring half the transmitted power.</p> / Master of Applied Science (MASc)

<p>A microprocessor based system to convert the Walsh spectrum of a frequency limited signal to its Fourier spectrum has been designed and built. The entire processing hardware is implemented on a single PLS-401 card, which consists of an Intel 4004 microprocessor, read only memories to store the conversion program and matrices of constants, random access memories to store results, and input/output ports. The converter can process up to 32 coefficients, and utilizes an 8-bit word length. For test purposes, the Walsh spectra are programmed into a read only memory, and the Fourier spectra are displayed in binary form on an LED matrix. The maximum conversion time is 1.81 seconds, and the maximum absolute error is 2.03% of the largest possible coefficient.</p> / Master of Science (MS)