In wireless transceiver circuits some of the most prevalent required off-chip components are discrete filters. These components are generally implemented with surface acoustic wave (SAW) or ceramic components. These devices are used in the receiver section for discrimination of incoming radio frequency (RF) signals as well as downconverted intermediate frequency (IF) signals. Presently, with the growing demand for multi-functional wireless consumer devices, the need for full integration of RF and logic circuits in wireless communications systems is becoming increasingly evident. If integrated RF filters with acceptable electrical characteristics could be realized, this might reduce or eliminate the currently required off-chip filters, prospectively decreasing the complexity, size, and cost of future wireless transceiver circuits and systems. The objective of the present research effort is to implement an integrated Q-enhanced LC bandpass filter in a prospective receiver front-end RF amplifier using the passive and active components available in a standard digital complementary metal-oxide semiconductor (CMOS) process. CMOS is the standard design medium for digital circuitry, and with the increased unity gain or transit frequency (fT) values that accompany steadily shrinking CMOS device sizes, the implementation of gigahertz frequency communications circuits in this medium is increasingly feasible. The circuit design specifically investigated in this work introduces a loss-compensated second-order gigahertz range bandpass filter implemented in a 0.18 쭠digital CMOS process provided by National Semiconductor. This filter incorporates a unique design technique that provides improvements in filter linearity through an independently variable bias level shifting method, while also facilitating prospective single-to-differential signal conversion. One distinctive characteristic of the investigated circuit, in comparison to other RF integrated filter work, is the implementation of a novel integrated transformer feedback method that facilitates magnetically coupled loss-restoration and subsequent filter Q-enhancement. Additionally, this loss restoration method is achieved using a single transistor, in contrast to the multi-transistor cross-coupled transconductor Q-enhancement technique commonly implemented in other previous and current integrated RF filter research.

In this thesis, we propose a new bandwidth-enhancement method of using a parasitic open slot to achieve a wide lower band for the internal laptop computer antenna with a small size to cover the GSM850/900 operation and a wide upper band to cover the GSM1800/1900/UMTS operation as well. The occupied antenna volume is only 48 ¡Ñ 10 ¡Ñ 3.5 mm^3 above the top edge of the display ground. For practical application, we analyze the effects of the antenna position, nearby metal plate, shielding metal plate, keyboard ground, FR4 substrate, and the size of display ground on the performance of the WWAN antenna. In addition, effects of the user¡¦s whole-body on the proposed antenna are also analyzed. Owing to the user¡¦s whole-body being mainly lossy materials, a decrease in the antenna¡¦s radiation efficiency is observed when the user¡¦s whole-body is in close proximity to the WWAN laptop computer antenna.

Based on the acquisition trajectory, PROPELLER MRI repeatedly sampled the center k-space in every blade, which was used to provide most of the energy of an image. The purpose of view sharing PROPELLER is to improve the spatio-temporal resolution of dynamic imaging by reducing the acquisition time of single frame to that of single blade. With the center k-space provided by only one blade, which is called the target blade, the high spatial-frequency components were appropriately contributed by a set of neighboring blades with different rotation angles, leading to the high spatial resolution after reconstruction. In this study, a flow phantom experiment with the injection of T1-shortening Gd-DTPA solution was performed to exam the feasibility and accuracy of view-sharing PROPELLER. Furthermore, cardiac imaging of healthy volunteer obtained by the proposed technique was also done with ECG gating to test the image quality without any injection of contrast agent. The in-vivo experiment was done with and without breath holding. In addition to slight aliasing artifact due to insufficient FOV, no other artifact was observed.

Molecular photoabsorption enhancement under ambient solar radiations can improve efficiency substantially in renewable energy production. Here, we explore the theoretical basis and experimental evidences that nanostructured molecular assemblies exhibit an unprecedented property of synergistic photon absorption enhancement. The molecular mechanism of this enhancement phenomenon originates from the combined effect of the photon-molecule interaction and the electronic energy transfer between two adjacent molecular assemblies. For a natural system, the synergistic photon absorption enhancement factor of green algae (Chlorella vulgaris) in vivo at 632.8 nm was determined to be 103. This enhanced photon absorption process in nanostructured molecular assemblies opens a doorway to create entangled double excitons by incoherent solar radiations.

This study focuses on hexagonally sampled images and grayscale morphology. We combine hexagonal image processing and grayscale morphology to develop hexagonal grayscale morphology, and propose an algorithm to detect and enhance edges. Hexagonal image processing consists of three important steps: conversion of hexagonally sampled images, processing, and display of processed images on simulated hexagonal grid. We construct four different sizes of hexagonal structuring elements to apply morphological operations on hexagonal images. In this study, we applied morphological gradient for edge detection and proposed algorithm for edge enhancement. Moreover, we developed six different shapes of structuring elements to find an optimum one. Finally, we assessed two methods to compare our results, and identified the best result and optimum structuring element. We expect that proposed algorithm will offer a useful tool of image processing on hexagonally sampled images.

The present work has been an experimental investigation to evaluate the applicability of gas turbine cooling technology. With the temperature of the mainstream gas entering the turbine elevated above the melting temperature of the metal components, these components must be cooled, so they can withstand prolonged exposure to the mainstream gas. Both external and internal cooling techniques have been studied as a means to increase the life of turbine components. Detailed film cooling effectiveness distributions have been obtained on the turbine blade platform with a variety of cooling configurations. Because the newly developed pressure sensitive paint (PSP) technique has proven to be the most suitable technique for measuring the film effectiveness, it was applied to a variety of platform seal configurations and discrete film flows. From the measurements it was shown advanced seals provide more uniform protection through the passage with less potential for ingestion of the hot mainstream gases into the engine cavity. In addition to protecting the outer surface of the turbine components, via film cooling, heat can also be removed from the components internally. Because the turbine blades are rotating within the engine, it is important to consider the effect of rotation on the heat transfer enhancement within the airfoil cooling channels. Through this experimental investigation, the heat transfer enhancement has been measured in narrow, rectangular channels with various turbulators. The present experimental investigation has shown the turbulators, coupled with the rotation induced Coriolis and buoyancy forces, result in non-uniform levels of heat transfer enhancement in the cooling channels. Advanced turbulator configurations can be used to provide increased heat transfer enhancement. Although these designs result in increased frictional losses, the benefit of the heat transfer enhancement outweighs the frictional losses.

High linearity transmitters and receivers should be used to efficiently utilize the available channel bandwidth. Power consumption is also a critical factor that determines the battery life of portable devices and wireless sensors. Three base-band and RF building blocks are designed with the focus of high linearity and low power consumption. An architectural attenuation-predistortion linearization scheme for a wide range of operational transconductance amplifiers (OTAs) is proposed and demonstrated with a transconductance-capacitor (Gm-C) filter. The linearization technique utilizes two matched OTAs to cancel output harmonics, creating a robust architecture. Compensation for process variations and frequency-dependent distortion based on Volterra series analysis is achieved by employing a delay equalization scheme with on-chip programmable resistors. The distortion-cancellation technique enables an IM3 improvement of up to 22dB compared to a commensurate OTA without linearization. A proof-of-concept lowpass filter with the linearized OTAs has a measured IM3 < -70dB and 54.5dB dynamic range over its 195MHz bandwidth. Design methodology for high efficiency class D power amplifier is presented. The high efficiency is achieved by using higher current harmonic to achieve zero voltage switching (ZVS) in class D power amplifier. The matching network is used as a part of the output filter to remove the high order harmonics. Optimum values for passive circuit elements and transistor sizes have been derived in order to achieve the highest possible efficiency. The proposed power amplifier achieves efficiency close to 60 percent at 400 MHz for -2dBm of output power. High efficiency class A power amplifier using dynamic biasing technique is presented. The power consumption of the power amplifier changes dynamically according to the output signal level. Effect of dynamic bias on class A power amplifier linearity is analyzed and the results were verified using simulations. The linearity of the dynamically biased amplifier is improved by adjusting the preamplifier gain to guarantee constant overall gain for different input signal levels.

In recent years, the electronic chip is continuously developing in turning high performance. This trend urges the heat sink of electronic chip to become gradually important, and then that will develop many type of heat sink, which is water-cooling system. Therefore, the purpose of this paper is designing a high efficiency water-cooling element (WCE). The present study mainly aims at three points to bring up: (1) The different type chamber make use of the CFD package software FLUENT to study the pressure drop, velocity field and turbulent intensity deposition. (2) The different plank thickness, thermal conductivity and convection heat transfer coefficient use finite difference method to solve heat diffusion equation, and to confer thermal resistance value. (3) Then, machined this designed WCE and then measured its thermal resistance value. The results show: (1) The pressure drop main effect parameter is inlet velocity. (2) The thermal resistance value main effect parameter is convection heat transfer coefficient. (3) The plank thickness is inverse proportion relation with thermal resistance value. (4) The surface temperature range and mean surface temperature should become reference index in heat sink developmental process. (5) The cooling performance of Type D WCE is optimum in this paper. (6) The design is cross groove on convection surface, which should reduce thermal resistance value.

License Plate Recognition (LPR) systems are frequently utilized in various access controls and security applications. In this thesis, an experimental constraint based real-time License Plate Recognition system is designed, and implemented in Java platform. Many of the available constraint based methods worked under strict restrictions such as plate color, fixed illumination and designated routes, whereas, only the license plate geometry and format constraints are used in this developed system. These constraints are built on top of the current Turkish license plate regulations. The plate localization algorithm is based on vertical edge features where constraints are used to filter out non-text regions. Vertical and horizontal projections are used for character segmentation and Multi Layered Perceptron (MLP) based Optical Character Recognition (OCR) module has been implemented for character identification. The extracted license plate characters are validated against possible license plate formats during the recognition process. The system is tested both with Turkish and foreign license plate images including various plate orientation, image quality and size. An accuracy of 92% is achieved for license plate localization and %88 for character segmentation and recognition.

Resolution is the most important criterion for the clarity of details on an image. Therefore, high resolution images are required in numerous areas. However, obtaining high resolution images has an evident technological cost and the value of these costs change with the quality of used optical systems. Image processing methods are used to obtain high resolution images with low costs. This kind of image improvement is named as superresolution image reconstruction. This thesis focuses on two main titles, one of which is the identification methods of blur parameters, one of the degradation operators, and the stochastic SR image reconstruction methods. The performances of different stochastic SR image reconstruction methods and blur identification methods are shown and compared. Then the identified blur parameters are used in superresolution algorithms and the results are shown.