The aim of this thesis is to do a research about three microwave design software packages and evaluate them with the purpose of getting the sharpest filter as possible and also know which one is more efficient in this task. In order to achieve this purpose we designed, simulated and tried to manufacture the same low-pass filter (using microstrip lines) in different software. This way we are able to compare features as the S-parameters of the filters, the possibilities they give us, how easy to use they are, how long takes us to run a simulation, how much deviation they have in the simulations and how much deviation we get in the measurements of the manufactured filters.   The filter has to be a low-pass filter with the cut off frequency at 1.8 GHz and a minimum attenuation of -26dB at 4.6 GHz.   The next step will be design of the 3 filters with the 3 different software. Once we have done the designs we are ready to do simulations and manufacture them in order to evaluate which one of them is more accurate and give us the best response.   To do the measurements we used a Vector Network Analyzer, in order to get the S-parameters, and a Vector Signal Generator and a Signal Analyzer in order to check the response of the filters with real signals.   Finally, as a conclusion, evaluating all the results we got we can say that ADS is the software package that has more positive points and therefore the best suited to our needs.

Microwave filters possessing various forms are essential components in radar, satellite, and mobile communication systems. Increased demands for low-loss, miniature filters that can be mass produced at low cost have provided a significant challenge reinforcing the need for improving or even replacing the conventional microwave filters. In recent years, the concept of Photonic/Electromagnetic Bandgap (PBG/EBG) structures has attracted the attention of the microwave engineering community. The main feature of PBG/EBG structures is the existence of a bandgap in the frequency spectrum of a propagating photonic/electromagnetic wave. The motivation for adopting EBG structures stems from their capability to eliminate unwanted wave propagations in various microwave devices. This thesis investigates and proposes novel planar microstrip filters employing EBG structures in the form of slots etched on the ground plane. Such filters are not only compact, but also can improve the RF performance in both the passband and the stopband. This proposed concept is further extended to implement low-loss tunable lowpass filters, both digital and analogue, by integrating tuning elements directly into the slots. Transmission line circuit models are developed to design the proposed microstrip filters and tunable lowpass filters. To verify the concept and the validity of the developed circuit models, theoretical and experimental results are presented and carefully compared. Currently, dielectric resonator (DR) filters have been widely employed in wireless and satellite communication systems. Over the past two decades, tremendous progress has been made to reduce the size, and enhance the in-band and out-of-band performance of DR filters. However, the current approaches for implementing DR filters are relatively expensive and hardly amenable to mass production. Cost reduction remains a key limiting factor that needs to be addressed now. A new configuration of DR filters is presented in this thesis. The novel concept simplifies the assembly, integration, and alignment of DR filters, significantly reducing production time and costs. Not only is the design of the proposed multi-pole DR filters and diplexers examined, but also the fabrication technique. The experimental measurement results confirm the validity of the theoretical designs of the new filters, which makes this concept very attractive for further applications in both wireless and satellite communication.

This thesis is concerned with the evolution of implicit or explicit surfaces. The first part of this thesis addresses three problems in fluid simulation: advection, thin film, and the volume error. First, we show that the back and forth error compensation and correction (BFECC) method can significantly reduce the dissipation and diffusion. Second, thin film is hard to simulate since it has highly complex liquid/gas interface that requires high memory and computational costs. We address this difficulties by using cell centered octree grid to reduce memory cost and a multigrid method to reduce computational cost. Third, the volume loss is an undesired side effect of the level set method. The known solution to this problem is the particle level set method, which is expensive and has small but accumulating volume error. We provide a solution that is computationally effective and can prevent volume loss without accumulation. The second part of this thesis is focused on filtering a triangle mesh to produce a mesh whose details are selectively reduced or amplified. We develop a mesh filter with a rational transfer function, which is a generalization from previously developed mesh filters. In addition, we show that the mesh filter parameters can be computed from the physical size of mesh feature.

The multi-scale mixed finite element method (MsMFEM) discussed in this work uses a two-scale approach, where the solutions to independent local flow problems on the fine grid capture the fine-scale variations of the reservoir model, while the coarse grid equations appropriately assimilate this information in the global solution. Temporal changes in porous media flow are relatively moderate when compared to the spatial variations in the reservoir. Hence, approximate global solutions by adaptively solving these local flow problems can be obtained with significant savings in computational time. The ensemble Kalman filter, used for real-time updating of reservoir models, can thus be coupled with the MsMFEM-streamline simulator to speed up the historymatching process considerably.

Many open-hole acid treatments are being conducted by pumping acid through jetting ports placed at the end of coiled tubing or drill pipe. The filter-cake on the bore-hole is broken by the jet; the acid-soluble material is dissolved, creating wormholes in the formation. This combination of two acting factors creates more stimulation beyond the jetting action area. Existing papers have mentioned the advantages of using jetting both for damage removal and as the preliminary stage before further acidizing. Many papers discuss theory and practical implementation of wormholing during acid jobs and the resulting injectivity enhancement, too. However, there is no complete research regarding jetting efficiency with regards to permeability restoration due to filter-cake disruption, and therefore, no data exists for efficient filter-cake removal by acid jetting just prior to wormholing. My project objective is to conduct experiments of acid jetting, defining the parameters that aid to restore injectivity. Based on the parameters obtained from the experiments, I developed a set of recommendations for acid jetting design and optimization.

The design and implementation of a dynamic voltage restorer (DVR) is presented in this thesis. The proposed DVR can restore the end-user voltage to its normal level by rapidly injecting a compensating voltage onto the power line against the upstream power disturbances. The control algorithm uses the concept of reference voltage tracking method. Based on the electric circuit theory, the filter of the DVR is also analyzed. Besides, performance of the proposed method is simulated and compared with other different control methods by using Matlab-simulink/PSB. The results show the effectiveness of the proposed method. A 2.18 KVA DVR prototype is implemented to verify the performance of the proposed method.

Abstract A feasible technique, using carrier-phase data from GPS and CCD camera, is presented to identify ground target location as well as azimuth angle of a low altitude aircraft/helicopter without using any gyroscope measurements; the baseline vector can also be identified using GPS compass. The ground target¡¦s image is extracted from background and recorded by image processing technique. By integrating ground target¡¦s location and the recorded GPS data, the designated states can be estimated by using extended Kalman filter technique. Basically, the extended Kalman filter does the state estimation job, and it¡¦s a nonlinear measurement process. By processing these time update and measurement update, the integer ambiguity as well as azimuth angle can be determined. The proposed GPS compass system consists of three componets : pointer, sensor, and controller. By using carrier-phase data from two GPS receivers, we can compute the baseline vector, whose length is equal to one meter, and achieve the direction accuracy within one degree. The integer ambiguity number is resolved by rotating the baseline vector; the conventional antenna swapping technique is a special case of the proposed method. Therefore, the GPS compass may replace these magnetic compass or gyroscope used in navigation system. By continuously snapping ground target image using CCD camera and utilizing the GPS receivers, the coordinate of the ground target can be identified. Simulation justifies the feasibility of the proposed scenario. Simulation has shown that the estimation errors for stationary and traveling with constant velocity ground targets are within 1.8 m and 6 m, respectively.

In this study, we propose and demonstrate a flat-top birefringent optical interleavers utilizing a new ring-cavity as a phase-shift element. The uniform performance over entire C-band is a result of the unique ring-cavity architecture which utilizes Fresnel reflections of the prism-air interface to provide the partial reflections. Unlike dielectric mirrors with thin-film coatings, the reflectivities of Fresnel reflection are insensitive to wavelength variations in the transmission band. In the ring-cavity based birefringent interferometer (RCBI) interleaver, the spectral transmission characteristics of the interleaver with a 25-GHz channel spacing exhibits a 0.5-dB passband larger than 17.5 GHz (70% of the channel spacing), a 25-dB stopband greater than 17.5 GHz (70% of the channel spacing), a channel isolation better than 28 dB, and insertion loss lower than 2.2 dB. In the ring-cavity based birefringent Sagnac interferometer (RCBSI) interleaver, the spectral transmission characteristics of the interleaver with a 25-GHz channel spacing exhibits a 0.5-dB passband larger than 18.1 GHz (72.5% of the channel spacing), a 25-dB stopband greater than 18.1 GHz (72.5% of the channel spacing), a channel isolation better than 36 dB, and insertion loss lower than 1.5 dB. The RCBSI interleaver requires less number of optical components and hence results in more than 0.7 dB and 2.5% improvements in the insertion loss and band utilization, respectively, when compared to the RCBI interleaver. Therefore, the novel RCBSI interleaver can be used in dense wavelength division multiplexing (DWDM) applications.

Nowadays, electronics has really flourished with the rapid progress in science and technology. Besides being light and efficient of the products, digitalization and faster speed are also required which make the problem of EMI, electromagnetic interference, become more serious. Newer power supplies using switching technology become smaller and smaller. However, they also produce EMI problems that need to be considered. In this thesis, we only address the conducted EMI. Generally, the noise is suppressed by adding a filter at the power-line end. Hence, the EMI filter plays an important role to the solution of conducted emission. The particular filter is related to the type of the conducted emission, including common-mode and differential-mode. As a result, it is a great help for an engineer to be able to separate the noise. There are several noise separators in the present days. We propose new separators, which are capable of detect common-mode and differential-mode separately. Our separators are low-cost, easily manufactured and are able to give exact noise readings without adjustment. Incorporating the known methods of filter design and combing programming measurement the filter design can be made automatic. One approach makes use of the spectrum analyzer, which is considered to be a relatively expensive instrument. We also propose another approach using oscilloscope. The time-domain measurement is performed and transformed into frequency domain using FFT. A realistic design example is shown to give satisfactory results.

Abstract A simple negative transimpedance amplifier is proposed. Because of inherent low input and output impedance, the frequency response is higher than that of the traditional operational amplifier. Using feedback, the operation frequency of amplifier can be extended. By using a simple feedback resistance, the amplifier¡¦s output level is stabilized without using common-mode feedback. The negative transimpedance amplifier as a common active element is versatile. The characteristics of these application circuits are dominated by the passive elements of the circuits. In the transimpedance-C bandpass filter and transimpedance-C lowpass filter, the , , and Q factor can be tuned. Owing to the negligible loading effect of the transimpedance amplifier, the single stage Rm-C biquad can be cascaded to high order filters. In the voltage controlled oscillator, the oscillation frequency can also be tuned.