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This thesis presents Design, Measurement and analysis for size reduction of the Coupled line micro strip Hairpin band pass filters (MHBPF’s). Hairpin filters are an interesting topic for microwave designers. These planar circuits are widely used in wireless transceivers and other microwave projects due to an easy design process. The filter design and analysis described in this paper can be used for wireless transceivers as well as for microwave links. Two techniques have been employed for the size reduction and four different filters have been designed. 1st Technique, Conventional Hairpin configuration uses folding of the normal λ/2 resonators into U shape. 2nd technique exploits the cross coupling of the resonators for further size reduction of the filters.  From 1st to last design, different properties of micro strip and couple lines have been analyzed, observed, and finally exploited to reach to a more compact solution. Agilent ADS have been used for the simulation process of the initial filters. Further on, AWR Microwave office has been used for the EM simulation part of the project and a detailed analysis for the size reduction with respect to the different properties of the materials used. Since insertion loss method is going to be used for the designs, low pass filter prototypes parameters are used for further conversion to band pass. The loaded Q factor and the mix coupling coefficients between resonators have been calculated from standard empirical equations. FR4 substrate is used for manufacturing process. RogersRO3210 has also been used as a substrate for 3-section design in AWR Microwave Office for the illustration of size reduction with respect to substrate properties. The design with FR4 substrate has been manufactured and tested. The results have been analyzed on Vector Network Analyzer and displayed in results sections.

This thesis focuses on the phenomenon of aliasing and its mitigation with two explicit filters, i.e., Shuman and Padé filters. The Shuman filter is applied to velocity components of the Navier--Stokes equations. A derivation of this filter is presented as an approximation of a 1-D “pure math” mollifier and extend this to 2D and 3D. Analysis of the truncation error and wavenumber response is conducted with a range of grid spacings, Reynolds numbers and the filter parameter, β. Plots of the relationship between optimal filter parameter β and grid spacing, L2-norm error and Reynolds number to suggest ways to predict β are also presented. In order to guarantee that the optimal β is obtained under various stationary flow conditions, the power spectral density analysis of velocity components to unequivocally identify steady, periodic and quasi-periodic behaviours in a range of Reynolds numbers between 100 and 2000 are constructed. Parameters in Pade filters need not be changed. The two filters are applied to velocities in this paper on perturbed sine waves and a lid-driven cavity. Comparison is based on execution time, error and experimental results.

Graduate

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No description available.

Superconducting microelectronics (SME) technology has the potential of realizing very high speed digital receivers capable of performing direct digitization of radio frequency signals with very low power consumption. The SME receiver is implemented on a single chip using Niobium based low temperature superconductive (LTS) Josephson Junction (JJ) technology by HYPRES. Analogue RF filters are still required at the receiver front end and are key components of the overall superconductor digital receiver. SME receivers usually require two types of RF filters; a wideband bandpass filter and a bandstop filter (a notch filter). The notch filter is required to eliminate interference and unwanted signals in the passband. In this thesis, design of highly miniaturized lumped element wideband and bandstop filters is investigated and some challenges are addressed. The filters are fabricated by the HYPRES process and therefore can be integrated with the SME receiver on the same chip. In a wideband filter, the coupling between the adjacent resonators is high. Achieving such a strong coupling is one of the challenges of designing wideband filters. The wideband filters realized with distributed elements usually suffer from very low spurious frequency. As the bandwidth of the filter becomes wider, the spurious peak of the second harmonic gets closer to the passband of the filter. In the first part of this work, the possibility of realizing lumped element superconducting bandpass filters (BPF) with a relative bandwidth of 80% is investigated. In the second part of the thesis, design and realization of lumped element superconducting bandstop filters (BSF) is discussed. The challenge for designing a bandstop filter is providing a good match over a wide frequency range. So narrowband inverters cannot be used. Instead, usually λ/4 matched transmission lines provide 90° phase shift between the resonators of a notch filter. The possibility of replacing the long transmission line with other means or eliminating the inverters and using both shunt and series resonators are investigated. Having both series and shunt resonators introduces some new challenges that are addressed in the thesis and discussed thoroughly. A tunable notch resonator is presented. The tunability is provided by a superconducting MEMS varactor that is realized in our group by doing some post processing on the device fabricated by HYPRES. The tunability range of the device at cryogenic temperatures is investigated. A 3-pole tunable BSF is also designed that uses the same tunable resonators. The tunability of the filter is investigated through simulation.