This thesis proposes a dB-linear programmable variable gain amplifier (VGA) and a voltage peak detector with digital calibration for FPW-based antibody sensing system. In the first topic, a dB-linear programmable variable gain amplifier is proposed. By using two source followers as the input terminals, input signals with very low DC offset could be received. The linear local-feedback transconductors are employed to be trans-condurctor-stage and load-stage. Besides, a reconfiguration method is used to reduce the layout area and improve the linearity of the gain to attain gain error less than 0.86 dB measured on silicon. In the second topic, a voltage peak detector with digital calibration is proposed. The voltage peak of the input sine-wave signal is sampled and held by using an integra-tor, a digital-to-analog converter, and a voltage comparator to generate a square-wave signal. Besides, the voltage error caused by the propagation delay could be calibrated by the proposed digital calibration method. The frequency of input signal is up to 20 MHz and the voltage error is justified to be less than 0.81 % by simulations.

Low size, low power, and wearable bio-signal recording systems require acquisition front-ends with high common-mode rejection for interference suppression and adjustable gain to provide an optimum signal level to a cascading analog-to-digital stage. This thesis presents the realization of microcontroller operated double-differential (DD) recording setup with automatic gain control (AGC) and automatic balance control, which can adjust the magnitude of recorded bio-potential signal to a target level and reject common-mode interference for full-bandwidth recording without filtering. Microcontroller code realizes the automatic control method of gain and balance adjustment by detecting, computing, and varying parameters to set timing clock pulses, which determine the gain magnitude and balance state. The automatic balance control compensates for imbalance in electrode interface impedance. The double-differential amplifier is implemented using two integrated variable gain amplifiers (ASIC) and one adder. Measured results of the variable gain amplifiers fabricated in 0.35 £gm CMOS technology show an input spot noise of 169 nV/¡ÔHz, a NEF below 10, and a circuit active area of 0.017 mm2 with a power consumption of 1.44 £gW. Measured results of the double-differential amplifier setup confirm interference suppression of 25.7 dB, tunable gain range of 39.6 dB, and 239 nV/¡ÔHz noise assuming ¡Ó10% interface mismatch. Practical measured examples incorporating the chips confirm gain control suitable for bio-potential recording and interference suppression in a balanced DD arrangement for electrocardiogram and electromyogram recording.

Rapid development of fiber-optic communications network requirements increasing in recent years, The WDM technology and invention of anhydrous optical fiber open the possibility for optical fiber transmission bands broaden form 1.3 £gm to 1.6 £gm. Chromium doped yttrium aluminum garnet crystal fiber has characteristic of 300 nm broadband. Therefore, it¡¦s strongly desirable to develop a broadband fiber amplifier, laser or other active components for extending the flexibility of system architecture design in optical fiber communication. A few-mode chromium doped yttrium aluminum garnet double-clad crystalline fibers has been demonstrated by employing a modified version of LHPG technique, means using silica-YAG crystal co-drawing and multiple core-tuning process by precisely controlled inter-diffusion between YAG core and silica tube. In this thesis, electron probe x-ray micro-analysis, energy dispersive spectroscopy and transmission electron microscopy were utilized to confirm this fiber structure and composition. This fiber has gross gain about 2.3 dB with dual pumped by few hundred mini Watt. Significantly reduce the pump power threshold. Compared with the last large core size, few-mode (small core size) chromium doped yttrium aluminum garnet double-clad crystalline fibers has lower heat effect and higher power efficiency. To enhance the optical properties towards few modes or even single mode, not only reduce the transmission loss, but improve the device efficiency. Key words: Laser heated pedestal growth, Cr4+:YAG, Double-clad Crystal Fiber, gain

Due to dramatic growth of capacity in optical fiber communication, the fiber dispersion has become one of major factors affecting the quality of optical signal transmission with different modulation scheme, leading to the importance in controlling optical chirp. Among the elements used for optical fiber communications, electroabsorption modulator (EAM) and semiconductor optical amplifier (SOA) are served as optical amplitude and phase modulation. In this work, EAM-integrated SOA is used to realize the pre-chirp technique through their inherently reversed phase modulation as well as amplitude modulation. In the experiment, tunable optical filter and a 10Gb/s data pattern are used for extracting the frequency chirp of the timely signal. With the positive chirp operation in EAM, it is found that the overall chirp of EAM-integrated SOA can be varied from 3GHz to -9GHz by adjusting current injection through SOA. Also, as inspecting the 10Gb/s pattern, the pattern effect can also be controlled by the reversed carrier dynamics between EAM and SOA. Finally, a 10Gb/s data transmission with 43km transmission is demonstrated by using such pre-chirp technique, showing that such technique can be applied to other type signal processing.

In the aspects of global sustainability, buildings are known to be one of the largest energy consumers. Though sustainable building construction through technological advances is helping in achieving environment friendly buildings, a considerable amount of energy is also being consumed by existing buildings. While many factors at all different stages of building life are responsible for this, the building material is one of the most important considerations. Glass being the most sensitive building material can lead to high energy consumption in the building if used in an improper way. This study takes this factor into account, and tries to investigate the potential of energy savings in buildings through the simple and basic considerations in design. An energy analysis model of an existing academic building in College Station, Texas was developed using Design Builder computer simulation software. This model was then analyzed for the total amount of energy consumption in the base case. The existing building model was then modified by replacing the glass used for external fenestrations. Latest building codes and standards for the site location, glass properties, and parametric simulation results were taken into consideration. Again the model was simulated for annual energy consumption and the results are noted. This formed the first option for the retrofitting scenario. A hypothetical redesign scenario was also established in which the revision of building orientation was taken into consideration. The building was re-oriented to suit the weather conditions and recommendations by Advanced Energy Design Guidelines (30 percent energy savings over ASHRAE Standard 90.1-1999). The building was then simulated for annual energy consumption. A comparative analysis was performed between the three cases and the study concluded by showing 23 percent savings in the annual fuel consumption, 23.35 percent reduction in CO2 emission of the building and 25 percent reduction in annual solar heat gain under Modified case 1. Modified case 2, however, did not show any further savings due to the form of the building (almost square). However, modified case 1 settings emitted 31.8 percent more CO2 over the Energy Star office building in Texas. This methodology sets up a set of guidelines which can be followed while investigating a building for minimum annual energy consumption.

Stability is a critical issue in gain-scheduled control problems in that the closed loop system may not be stable during the transitions between operating conditions despite guarantees that the gain-scheduled controller stabilizes the plant model at fixed values of the scheduling variable. For Linear Parameter Varying (LPV) model representations, a controller interpolation method using Youla parameterization that guarantees stability despite fast transitions in scheduling variables is proposed. By interconnecting an LPV plant model with a Local Controller Network (LCN), the proposed Youla parameterization based controller interpolation method allows the interpolation of controllers of different size and structure, and guarantees stability at fixed points over the entire operating region. Moreover, quadratic stability despite fast scheduling is also guaranteed by construction of a common Lyapunov function, while the characteristics of individual controllers designed a priori at fixed operating condition are recovered at the design points. The efficacy of the proposed approach is verified with both an illustrative simulation case study on variation of a classical MIMO control problem and an experimental implementation on a multi-evaporator vapor compression cycle system. The dynamics of vapor compression systems are highly nonlinear, thus the gain-scheduled control is the potential to achieve the desired stability and performance of the system. The proposed controller interpolation/switching method guarantees the nonlinear stability of the closed loop system during the arbitrarily fast transition and achieves the desired performance to subsequently improve thermal efficiency of the vapor compression system.

This thesis consists of two parts. Part one includes the design procedure and implementation of the building blocks for an RF tuner module used in the Digital Video Broadcasting ¡V Terrestrial ¡]DVB-T¡^system. It contains the comparison of several RF tuner architectures, frequency planning, and link-budget analysis. Measurement results for the designed tuner operating in the frequency range from 50 to 860 MHz show that the maximum power gain ranges from 49 to 57.6 dB. The entire range for gain control is over 60 dB. In the maximum gain state, the noise figure ranges form 6.8 to 11.5 dB, the output third-order interception point¡]OIP3¡^ranges from 11.7 to 13.8 dBm, and the image rejection is over 50 dB. By applying the simplified single-carrier modulation signals, the tuner can pass the DVB-T system specifications with respect to the adjacent-channel and overlapping-channel protection ratios. In part two, an RFIC design for low-noise variable-gain amplifier that can be used in the RF front end of DVB-T system is presented. It operates from 100 to 900 MHz and dissipates 59.4 mW under a 3.3-V power supply. In the maximum gain state, measurement results for this RFIC show that the noise figure is less than 4 dB, the maximum gain is more than 14 dB, and the OIP3 is about 6.8dBm. The entire gain control range is over 40 dB.

Conventional fixed threshold detectors set a fixed threshold based on the overall statistical characteristics of the spatially uniform clutter over all ranges to give a specific probability of false alarm and detection. However, in radar applications clutter statistics are not known a priori. Constant False Alarm Rate (CFAR) techniques provide an adaptive threshold to estimate the clutter statistics and to distinguish targets from clutter. In Cell Averaging CFAR (CA-CFAR) the threshold is controlled by averaging the fixed size CFAR cells surrounding the cell under test. In this thesis, radar detection of targets in sea clutter modelled by compound Kdistribution is examined from a statistical detection viewpoint by Monte Carlo simulations. The performance of CA-CFAR processors is analysed under varying conditions of sea clutter spatial correlation and spikiness for several cases of false alarm probability, the length of cell size used in the CFAR processor and the number of pulses integrated prior to CA-CFAR processor. v The detection performance of CA-CFAR is compared with the performance of fixed threshold detection. The performance evaluations are quantified by CFAR loss. CFAR loss is defined as the increase in average signal to clutter ratio compared to that of fixed threshold, required to achieve a given probability of detection and probability of false alarm. Curves for CFAR loss to the spikiness and spatial correlation of clutter, number of pulses integrated and the length of cell size are presented.

The mechanism of weight gain due to treatment with olanzapine, a serotonin receptor antagonist, has not been fully understood. Weight gain and food intake are under the control of neuropeptides/hormones, POMC (proopiomelanocortin), CART (cocaine and amphetamine regulated transcript), AgRP (Agouti-related peptide) and NPY (neuropeptide Y) that are synthesized and secreted from the arcuate nucleus (ARC) of hypothalamus. In this study, the altereration of the ARC neuropeptide/hormone levels both in humans and rats were determined as one of the weight gain mechanism. To examine olanzapine&rsquo / s weight gain effects, male first attack psychotic patients (pre-treatment), were hospitalized and treated for 4 -weeks (post-treatment), (n = 22), and healthy control group (n = 26) were included to the study. Case-control association design was used to analyze the changes in body mass index (BMI), peripheral leptin and the ARC neuropeptides levels. In patients, after 4-weeks of the olanzapine treatment / BMI and the waist circumference were significantly increased with average weight gain of 4.33 kg. In pre-treatment group, NPY levels were significantly lower while &alpha / -MSH, the anorexigenic product of POMC levels were significantly higher vs. control. At post-treatment, both leptin and NPY levels were significantly increased but the CART levels did not change. To further understand the underlying mechanism of olanzapine induced weight gain, the drug was orally administrated to 10 healthy male Wistar rats to analyze both the hypotalamic gene expression and peripheral levels of those candidate neuropeptides. In rats food consumption was increased and hypotalamic mRNA levels of NPY, AgRP and POMC were decreased while CART levels did not show any alteration. Consistent with the expression data, circulating levels of NPY, AgRP and &alpha / -MSH decreased significantly but CART levels were also reduced unexpectedly. In conclusion, it may be presumed that the antagonistic effect of olanzapine on the ARC neurons might be the basis for a disregulation of the neurohormones secretion which may cause weight gain in the treated psychotic patients.

There has been much effort in new design for transceiver used in mobile communications. The general approach is to combine RF functions with DSP to allow linear modulation techniques and permit flexibility of modulation format and receiver processing. In practice, with the quadrature modulation technique there is always some imbalance between the I- and Q channels of modulator and demodulator. This is mainly due to finite tolerances of capacitor and resistor values used to implement the analog components. The unavoidable imbalance between the I- and Q channels is known to degrade the performance of quadrature communication system. The main concern of this thesis is to propose a new blind scheme and with fast convergence algorithm, such as the inverse QRD-RLS algorithm, to deal with the problem described above for compensation in the transmitter and receiver. First, for the transmitter, the so-called adaptive estimation and compensation with power measurement implemented by the inverse QRD-RLS algorithm is employed. While in the receiver, a new blind adaptive filtering approach of the nonlinear parameters estimation and compensation, along with the power measurement in the receiver, is devised to adaptively compensate for the gain/phase imbalance and DC offsets in a quadrature demodulator. Where the conventional inverse QRD-RLS algorithm is employed for estimating the parameters of compensator, without using any reference signal transmitted from the transmitter. To document the merits of the proposed scheme, computer simulation for the coherent 16-PSK-communication system is carried out. With our proposed method a great improvement for eliminating the effects of the imbalance and offset over the existing techniques has verified. It has rapidly convergence rate and the smaller mean square error in steady state.