The notion of designing circuits based on charge sensing, charge adaptation, and charge programming is explored in this research. This design concept leads to a low-power capacitive sensing interface circuit that has been designed and tested with a MEMS microphone and a capacitive micromachined ultrasonic transducer. Moreover, by using the charge programming technique, a designed floating-gate based large-scale field-programmable analog array (FPAA) containing a universal sensor interface sets the stage for reconfigurable smart sensory systems. Based on the same charge programming technique, a compact programmable analog radial-basis-function (RBF) based classifier and a resultant analog vector quantizer have been developed and tested. Measurement results have shown that the analog RBF-based classifier is at least two orders of magnitude more power-efficient than an equivalent digital processor. Furthermore, an adaptive bump circuit that can facilitate unsupervised learning in the analog domain has also been proposed. A projection neural network for a support vector machine, a powerful and more complicated binary classification algorithm, has also been proposed. This neural network is suitable for analog VLSI implementation and has been simulated and verified on the transistor level. These analog classifiers can be integrated at the interface to build smart sensory systems.

No description available.

Call number: LD2668 .T4 1984 R33 / Master of Science

Students at Uppsala University have for some years been given the opportunity to take courses in subjects directly, or indirectly, related to the fields of signal processing and signal analysis. According to the directors of these courses, a considerable number of students are recurringly having difficulties grasping different concepts related to this field of study. This report covers a tool that easily allows teachers to visualize and listen to different manipulations of signals, which should help students get an intuitive understanding of the subject. Features of the system include multiple kinds of analog filters, sampling with variable settings and zero-order hold reconstruction. The finished system is flexible, tunable and modifiable to the teachers every need, making it usable for a wide variety of courses involving signal processing. The system meets its requirements even though individual components’ results de- viate slightly from ideal values. / Studenter vid Uppsala Universitet har, under ett antal år, givits möjligheten att läsa kurser inom ämnen direkt, eller indirekt, relaterade till signalbehandling/signalanalys. Enligt kursansvariga för dessa kurser har en ansenlig andel av studenterna svårigheter med att förstå en del av de begrepp och fenomen som förekommer under kurserna. Denna rapport behandlar ett verktyg som ger lärare i dessa kurser möjlighet att på ett enkelt sätt visualisera och lyssna på olika manipulationer av signaler, vilket bör hjälpa studenterna bygga en intuition för ämnet. Systemets olika funktioner inkluderar flera olika typer av analoga filter, sampling med olika inställningar, och så kallad ’Zero-Order-Hold’ rekonstruktion. Det resulterande systemet är flexibelt, inställbart och modifierbart till användarens behov, vilket gör det applicerbart i flera kurser som innefattar signalbehandling/analys. Systemet möter kraven som ställs, även fast resultaten hos individuella komponenter avviker aningen från ideala värden.

published_or_final_version / Electrical Engineering / Master / Master of Science in Engineering

Conventionally, the performances of Analog and Mixed-Signal (AMS) circuits have been characterized using specification-based functional tests. In these test methods, the correct functionalities of AMS circuits are verified by measuring pre-determined specification parameters of AMS circuits. The conventional test methods provide accurate test results by using various test equipments which generate functional test signals and capture the test responses externally. However, due to rapid increase in the performance of AMS circuits in recent years, the conventional test methods face various challenges in the aspects of test cost, test time and testability. The goal of this dissertation is to develop innovative functional test methods for AMS circuits which are aimed at reducing the test cost and test time while providing comparable test accuracy to the conventional test methods. To achieve this goal, efforts have been made to explore the characteristics of AMS circuits in a system level and to research efficient performance characterization methods based on the system level modeling of Devices Under Test (DUTs). As a part of these efforts, the pseudorandom test methods for nonlinear AMS circuits have been developed. In these methods, the pseudorandom signal is used to excite the DUT and to generate the test response which has sufficient information to characterize DUT performances. The pseudorandom test methods use the Volterra series model to capture the nonlinear behaviors of AMS circuits and to calculate various specification parameters of the DUT using the pseudorandom test response. In doing so, the performances of nonlinear AMS circuits can be characterized straightforwardly and accurately using a low-cost test setup. Also, in an effort to reduce the test time, parallel test methods of AMS circuits have been developed in which multiple DUTs are tested simultaneously by sharing a common test setup. In these methods, the test responses generated from different DUTs are combined together and the resulting composite test response is used to characterize the performance of each DUT individually. This will reduce the use of tester resources and will increase the test throughput beyond the level limited by the test equipments. The spectral characteristics of test stimulus are studied along with the system level behavior of AMS circuits to develop the efficient parallel test methods. Finally, in order to consider the practical issue of generating at-speed test stimuli for high-speed DUTs using a low-cost test setup, a reconfigurable built-off test interface is developed which can be used to generate various test patterns, including high-speed pseudorandom signal, using a low-speed tester. / text

<p>The purpose of this report was to study how the Swedish radio channel Sveriges Radio (SR) website changed over time. What are the differences between various media websites? How many people listen to normal and web-radio and what are the differences between the various services offered on the SR website?</p><p>Reports from the BBC, Statistics Sweden, Mediavision and the Swedish National Post and Telecom Agency were compared. Several theoreticians have been studied, including Donald A Norman, Jonas Löwgren, Karen Holtzbratt, Jacob Nielsen and Geoffrey Moore.</p><p>The method used by the author comprised a systematic mapping of statistics from webTrends, KiaIndex, SiteCensus, TNS Gallup/K2analys and reports from RUAB. The data studied have been collected from telephone interviews, postal surveys, internet panels, and from log files. The statistics have then been compared and in some cases tables have been cross-correlated.</p><p>The results from the various studies showed that SR is following the rising trend displayed by a few of the media websites reviewed. It is of particular interest to note that web-radio listening between the final period 2004 and 2005 almost doubled.</p><p>The next stage will be to offer the listener/user a more central position. By listening to users, and above all non-users, the function and content can be adapted to the larger group of pragmatists and conservative listeners that are looking for sustainable and convenient solutions.</p><p>Key words [Streaming, on demand, radio, analogue, web-radio]</p> / <p>Avsikten med den här rapporten var att ta reda på hur Sveriges Radios (SR) sajt förändras över tid. Vilka skillnader finns det mellan olika mediesajter. Hur många lyssnar på vanlig- kontra webbradio samt vad finns det för skillnader mellan olika tjänster på SR:s sajt.</p><p>Jämförelser har gjorts mellan BBC, SCB, Mediavision samt Post & Telestyrelsens rapporter. Flera teoretiker har studerats som Donald A Norman, Jonas Löwgren, Karen Holtzbratt, Jacob Nielsen och Geoffrey Moore.</p><p>Författarens metod bestod av att systematiskt kartlägga statistik från webTrends, KiaIndex, SiteCensus, TNS Gallup/K2analys samt RUAB:s rapporter. De data som undersökts kommer från telefonintervjuer, postenkäter, Internetpaneler samt loggfiler. Statistiken har jämförts med varandra samt i vissa fall har tabellerna korskörts.</p><p>Resultaten från de olika undersökningarna visar att SR följer den uppåtgående trend som några av de undersökta mediesajterna har. Men det mer intressanta är att webbradiolyssningen mellan sista perioden 2004 och 2005 nästan fördubblats.</p><p>Nästa steg blir att se till att lyssnarna/användarna står mer i centrum. Genom att lyssna på användare, men framför allt icke-användare så skulle funktion och innehåll kunna anpassas till den större gruppen pragmatiker och konservativa som vill ha hållbara och bekväma lösningar.</p>

Delta-Sigma Analog-to Digital Converters have recently become important for providing high resolution with monotonicity and reasonable signal-to-distortion ratings without the need for laser trimming techniques. This has come about because of the recent ability to combine both extensive digital computation power, and switched-capacitor analog circuitry on a monolithic chip. Delta-Sigma converters have primarily been used, however, in signal processing applications, notably digital audio, but not for instrumentation. The purpose of this dissertation is to provide a high accuracy, DC-accurate, Delta-Sigma Analog-to-Digital converter in monolithic form. Autocalibration gives endpoint correction, and chopper stabilization minimizes the effect of parameter shifts, drift, and flicker noise. A digital filter, needed for all Delta-Sigma converters, serves as a signal processor to reject out-of-band noise and resonant responses of the external system. A 3-micron, double-poly CMOS process is used. Power requirements are +/- 5 Volts. A six-pole Gaussian IIR digital filter is chosen for good transient response and no overshoot. The filter algorithm and hardware solve the difference equations of a low-pass switched-capacitor prototype filter in digital form. Due to the low bandwidth needed, an area-efficient shift-and-add architecture is used. The area is further reduced with a novel multiplication algorithm, and the logic is reused to perform the calculations required for calibration. The system level device performance is verified in FORTRAN. The analog subcircuits are simulated over process and temperature corners in HSPICE. Measurements show differential and integral linearlity, DC accuracy and noise near the 20-bit level. Power supply rejection, and out-of-band signal attenuation are good, and the step response is monotonic. The circuit is marketed as Crystal Semiconductor CSC5503 and CSC5501 (20 and 16-bit resolutions, respectively).

International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / Chart recorders currently in use on telemetry ranges are connected to telemetry processors via a series of Digital to Analog Converters (DAC) systems. A new modular interface system receives data directly from the processor broadcast bus and distributes them to up to ten digital chart recorders. This interface is programmed from a computer to assign individual tags to each one of the display channels. This system eliminates DAC's and patch panels. It simplifies display system operation, speeds up transition from test to test and reduces maintenance costs.

A photonic analog-to-digital converter (ADC) based on a robust symmetrical number system (RSNS) was constructed and tested. The analog signal to be converted is used to amplitude modulate an optical pulse from a laser using three Mach-Zehnder interferometers (MZI). The Mach-Zehnder interferometers fold the input analog signal for a three-channel RSNS encoding. The folding waveforms are then detected and amplitude-analyzed by three separate comparator banks, the outputs of which are used to determine a digital representation of the analog signal. This design uses the RSNS preprocessing to encode the signal with the fewest number of comparators for any selected bit resolution. In addition to the efficiency of its use of comparators, the RSNS encoding has inherent Gray-code properties making it particularly attractive for eliminating any possible encoding errors. The RSNS encoding is combined with an optical infrastructure that offers high bandwidth and low insertion loss characteristics. A full implementation was constructed and tested. The lack of a high-speed data acquisition device limited the results to examining the preprocessing and digital processing separately. With the system integration of a data acquisition device, a wideband direct digital antenna architecture can be demonstrated.