Thanks to the advance in CMOS technology, an extensive category of applications has been migrated from traditional BJT-based processes. System-on-a-Chip (SoC) realization of digital, analog, and even high voltage devices is now a reality. To address the challenge imposed by integrating analog and high voltage devices in standard CMOS processes, this thesis aims at the design of three specific topics in particular. With regard to the contents of the thesis, first of all, the theory of linear-in-dB automatic gain control (AGC) is discussed. In succession, a linear-in-dB variable gain amplifier (VGA) is mentioned. The implementation of a Feed-forward Output Swing Prediction AGC featuring a Prediction Parallel-Detect Single-Store Peak Detector (PDSSPD) and a High Input/Output Swing VGA is also described. Furthermore, a digitally programmable gain amplifier for a ZigBee wireless receiver is also mentioned. In response to the advent of CMOS-compatible high voltage tolerant Bipolar-CMOS-DMOS (BCD) process, an operational amplifier for level converting operation is disclosed. A 60-V Li-ion battery charger has also been proposed, along with a novel battery charge mode, namely, the incremental charge (IC) mode. Practical issues regarding the high voltage tolerant BCD process is also briefly discussed. Finally, a backplane transmitter featuring pre-emphasis and a receiver utilizing decisive feedback equalization (DFE) designed for CIC MorPack technology are presented. When packaged in a Leadless Ceramic Carrier (LCC) package, the transmitter can transmit up to 500 Mbps and the receiver can receive up to 125 Mbps, both through DuPont connectors without impedance matching.

Jitter requirements have become more stringent with higher speed serial communication links. Reducing jitter, with the main focus on reducing data dependant jitter (DDJ), is presented by employing adaptive finite impulse response (FIR) filter pre-emphasis. The adaptive FIR pre-emphasis is implemented in the IBM 7WL 0.18 µm SiGe BiCMOS process. SiGe heterojunction bipolar transistors (HBTs) provide high bandwidth, low noise devices which could reduce the total system jitter. The trade-offs between utilising metal oxide semiconductor (MOS) current mode logic (CML) and SiGe bipolar CML are also discussed in comparison with a very high fT (IBM 8HP process with fT = 200 GHz) process. A reduction in total system jitter can be achieved by keeping the sub-components of the system jitter constant while optimising the DDJ. High speed CML circuits have been employed to allow data rates in excess of 5 Gb/s to be transmitted whilst still maintaining an internal voltage swing of at least 300 mV. This allows the final FIR filter adaptation scheme to minimise the DDJ within 12.5 % of a unit interval, at a data rate of 5 Gb/s implementing 6 FIR pre-emphasis filter taps, for a worst case copper backplane channel (30" FR-4 channel). The implemented integrated circuit (IC) designed as part of the verification process takes up less than 1 mm2 of silicon real estate. In this dissertation, SPICE simulation results are presented, as well as the novel IC implementation of the proposed FIR filter adaptation technique as part of the hypothesis verification procedure. The implemented transmitter and receiver were tested for functionality, and showed the successful functional behaviour of all the implemented CML gates associated with the first filter tap. However, due to the slow charge and discharge rate of the pulse generation circuit in both the transmitter and receiver, only the main operational state of the transmitter could be experimentally validated. As a result of the adaptation scheme implemented, the contribution in this research lies in that a designer utilising such an IC can optimise the DDJ, reducing the total system jitter, and hence increasing the data fidelity with minimal effort. / Dissertation (MEng)--University of Pretoria, 2011. / Electrical, Electronic and Computer Engineering / unrestricted

The objective of my thesis is to measure magnetic field gradient decay in an MR tomograph, process and evaluate the data measured and analyse the issue. The theoretical section focuses on the reasons for the gradient distortion which has a negative impact on NMR measuring techniques and it also describes options to eliminate the negative effects, focusing mainly on pre-emphasis filtration. It also lists methods of gradient magnetic field measuring. The practical section contains results of magnetic field decay measurements taken with the tomograph in the Institute of scientific instruments of the Academy of sciences in Brno using the method of instantaneous frequency with and without pre-emphasis compensation. The data are processed with MAREVISI and MATLAB programmes. MATLAB is used to develop a modern method of filtration to eliminate noise in useful signal leading to more accurate measurements of MR magnetic fields. This filtration uses a method of time-dependent variable thresholds and two-channel filter banks. MATLAB is also used to design a programme for approximation of the measured gradient magnetic field decay. The decay must be approximated in order to obtain time constants and the degree of exponential decay, which serve to set up the pre-emphasis compensation.

During musical performance and recording, there are a variety of techniques and electronic effects available to transform the singing voice. The particular effect examined in this dissertation is breathiness, where artificial noise is added to a voice to simulate aspiration noise. The typical problem with this effect is that artificial noise does not effectively blend into voices that exhibit high vocal effort. The existing breathy effect does not reduce the perceived effort; breathy voices exhibit low effort. A typical approach to synthesizing breathiness is to separate the voice into a filter representing the vocal tract and a source representing the excitation of the vocal folds. Artificial noise is added to the source to simulate aspiration noise. The modified source is then fed through the vocal tract filter to synthesize a new voice. The resulting voice sounds like the original voice plus noise. Listening experiments were carried out. These listening experiments demonstrated that constant pre-emphasis linear prediction (LP) results in an estimated vocal tract filter that retains the perception of vocal effort. It was hypothesized that reducing the perception of vocal effort in the estimated vocal tract filter may improve the breathy effect. This dissertation presents adaptive pre-emphasis LP (APLP) as a technique to more appropriately model the spectral envelope of the voice. The APLP algorithm results in a more consistent vocal tract filter and an estimated voice source that varies more appropriately with changes in vocal effort. This dissertation describes how APLP estimates a spectral emphasis filter that can transform the spectral envelope of the voice, thereby reducing the perception of vocal effort. A listening experiment was carried out to determine whether APLP is able to transform high effort voices into breathy voices more effectively than constant pre-emphasis LP. The experiment demonstrates that APLP is able to reduce the perceived effort in the voice. In addition, the voices transformed using APLP sound less artificial than the same voices transformed using constant pre-emphasis LP. This indicates that APLP is able to more effectively transform high-effort voices into breathy voices.

The thesis deals with the recognition of Parkinson's disease from the speech signal. The first part refers to the principles of speech signals and speech signals by patients suffering from Parkinson's disease. Further, it continues to describe the issues of speech signals processing, basic symptoms used for diagnosis of Parkinson's disease (e. g. VAI, VSA, FCR, VOT etc.) and reduction of these symptoms. The next part focuses on a block diagram of the program for the diagnosis of Parkinson's disease. The main objective of this thesis is comparison of two methods of feature selection (mRMR and SFFS). For classification have selected two different methods were used. The first method is classification kNN and second method of classification is Gaussian mixture model (GMM).

Tato disertační práce je obsahově zaměřená na problematiku integrity signálů v moderních čipových obvodech. Na základě provedených simulací a praktických experimentů byl proveden návrh equalizační techniky druhého řádu pro efektivnější vysokorychlostní komunikaci. Předložený návrh respektuje současné požadavky na vyvíjené signalizační techniky, které zahrnují efektivnější využití šířky pásma přenosového kanálu a energetickou úsporu. Provedené analýzy podrobně ukazují možnost zvýšení přenosové rychlosti při přenosu signálu skrz nízkonákladové přenosové kanály s využitím navržené signální metody. Výkonnost navrhované signalizační techniky je demonstrována na různých typech přenosových kanálů s přenosovou funkcí vyššího řádu. Diskutovány jsou rovněž možnosti omezení rušivých vlivů na přenosové kanály během návrhu.