Strong demands for smaller, cheaper, and multifunction wireless systems have put very stringent requirements on passive devices, such as inductors and capacitors. This is especially true considering the size and weight of most radio frequency (RF) transceivers are mainly due to passives. RF micro-electro-mechanical-systems (MEMS) passives are addressing this issue by offering lower power consumption and losses, higher linearity and quality (<i>Q</i>)-factors, potential for integration and miniaturization, and batch fabrication. These advantages position RF MEMS passives as good candidates to replace conventional passives. Further, they also open an opportunity for using the passives as building blocks for lumped element-based RF circuits (e.g. Flters, couplers, etc.) which could replace the more-bulky distributed-element circuits.<p> This thesis presents the design, simulation, fabrication using the deep X-ray lithography process, and testing of thick-metal RF inductors and their applications to lumped-element low-pass Filter (LPF) circuits. The 70-um tall single-turn loop inductors are structurally compatible to a pre-existing RF MEMS capacitor concept and allow the two device types to be fabricated together. This compatibility issue is crucial if they would be used to construct more complex RF circuits.<p> At a 50-Ohm inductive reactance point, test results show <i>Q</i>-factors of 17- 55, self-resonant frequencies (SRF) exceeding 11 GHz, and nominal inductances of 0.4- 3 nH for 1-loop inductors and <i>Q</i>-factors of 11- 42, SRFs of 4- 22 GHz, and inductances of 0.8- 5.5 nH for 2-loop inductors. Further, test results reveal that high conductivity metals improve the <i>Q</i>-factors, and that low dielectric-constant substrates increase the SRFs.<p> In terms of LPFs, measurements show that they demonstrate the expected third-order Chebyshev response. Two nickel Filters on a quartz glass substrate show a 0.6-dB ripple with 3-dB frequencies (<i>f</i>-3dB) of 6.1 GHz and 11.9 GHz respectively. On an alumina substrate, they exhibit a 1.4-dB ripple with <i>f</i>-3dB of 5.4 GHz and 10.6 GHz respectively. The filters are 203- 285 um tall and feature 6- 6.5 um wide capacitance air gaps. These dimensions are different than the original designs and the filter performances were shown to be somewhat sensitive to these discrepancies. Compared to a distributed approach, the lumped-element implementations led to an area reduction of up to 95%.

In this report the analysis of microstrip electrodynamic structures on basis of high-temperature superconductors is carried out and a mathematical model of microstrip devices with lumped and distributed nonlinear properties is created. For this purpose nonlinear integral equations method and method of moments are used. In the issue of the work a SHF filter based on the equivalent circuit of elements with lumped parameters is also studied. It is ascertained that the received mathematical model allows to achieve more proper results of modeling on compensation of variation of current-density distribution nearby the edges of conductor break.

This thesis addressed non-smooth dynamics of lumped parameter systems, and was restricted to Filippov-type systems. The main objective of this thesis was twofold. Firstly, modeling aspects of Filippov-type non-smooth dynamical systems were addressed with an emphasis on the constitutive assumptions and mathematical structure behind these models. Secondly, robust algorithms were presented to obtain numerical solutions for various Filippov-type lumped parameter systems. Governing equations were written using two different mathematical approaches. The first approach was based on differential inclusions and the second approach was based on differential-algebraic equations. The differential inclusions approach is more amenable to mathematical analysis using existing mathematical tools. On the other hand, the approach based on differential-algebraic equations gives more insight into the constitutive assumptions of a chosen model and easier to obtain numerical solutions. Bingham-type models in which the force cannot be expressed in terms of kinematic variables but the kinematic variables can be expressed in terms of force were considered. Further, Coulomb friction was considered in which neither the force can be expressed in terms of kinematic variables nor the kinematic variables in terms of force. However, one can write implicit constitutive equations in terms of kinematic quantities and force. A numerical framework was set up to study such systems and the algorithm was devised. Towards the end, representative dynamical systems of practical significance were considered. The devised algorithm was implemented on these systems and the results were obtained. The results show that the setting offered by differential-algebraic equations is appropriate for studying dynamics of lumped parameter systems under implicit constitutive models.

Exergy utilization calculations have been in the past repeatedly used to quantify the quality and quantity of energy used in thermal energy processes. This thesis is an attempt to derive a common language exergy utilization and compare for the first time two entirely different manufacturing processes, namely material processing by a mechanical method of straining of the material and simple heating of the same mass of the material using exergy utilization as a metric. The exergy utilization of material processing is determined by performed work and utilized heat transfer using 1) Ramberg-Osgood equation and 2) Lumped heat capacitance method. A comparison of these two methods is presented.

Thermal modeling is an important aspect of electric motor design. Numerous techniques exist to predict the temperatures in a motor, and they can be incorporated in the design of a thermal model for a new type of electric motor. This work discusses the available modeling techniques and determines which methods are applicable for medium-sized motors with either natural convection or forced convective cooling over irregular geometry. A time-dependant thermal model, with thermal transport parameters based upon geometric and simplified air flow information, is developed based on a discrete lumped parameter model with several modifications to improve accuracy. The model was completed with the aid of nine experiments, and the result is a thermal model that exhibits an absolute error of less than 6.1??C for the nine test runs at three different currents between 8.4 A rms and 28.2 A rms and three cooling levels, natural, 10.7 CFM and 24.4 CFM.

Flow control is an area of research of particular interest within automotive and aerospace industries since methods used to affect the fluid flow around vehicles can reduce drag and therefore lower their fuel consumption. One of these methods, which has generated a lot of interest in later years, is called active flow control and uses different types of actuators to impact the surrounding flow. In this thesis a model of a piezoelectric actuator for active flow control has been developed using Lumped Element Modelling and equivalent circuits. This approach, together with the chosen software for implementation, Simulink, provides models which are easy to simulate and evaluate. The actuator model has been validated using a novel methodology with sub-models with the purpose of reducing computational costs. The actuator is therefore divided into two submodels,one for structural and one for fluid dynamics, which are validated separately. This enables the use of simple yet accurate FEM and CFD models instead of time consuming FSI software which the complete model requires. The three implemented models have been validated using cases presented in previous studies and data from CFD-simulations. The results show that the decoupled models can be validated separately and its results can be integrated into the complete model, although further tests with a real actuator is needed. In addition to the modelling, a parameter study of the actuator has been performed in order to prepare for prototype design.

This study is concerned with whiplash injuries resulting from the sudden acceleration and deceleration of the head relative to the torso in vehicle collisions. Whiplash is the most common automobile injury, yet it is poorly understood. The objective of this thesis is to develop a representative rigid linkage lumped parameter model using Lagrangian mechanics to capture the relative motion of the head and cervical spine. Joint locations corresponding to the intervertebral centers of rotation are used to simulate the normal spinal movements and an inverse analysis is applied to determine the viscoelastic parameters for the spine, based on cadaver test results. The model is further validated using ANSYS dynamic finite element analysis and experimentally validated using a newly designed and fully instrumented whiplash test fixture. Our findings reveal the effectiveness of the simplified model which can be easily scaled to accommodate differences in collision severity, posture, gender, and occupant size.

This study is concerned with whiplash injuries resulting from the sudden acceleration and deceleration of the head relative to the torso in vehicle collisions. Whiplash is the most common automobile injury, yet it is poorly understood. The objective of this thesis is to develop a representative rigid linkage lumped parameter model using Lagrangian mechanics to capture the relative motion of the head and cervical spine. Joint locations corresponding to the intervertebral centers of rotation are used to simulate the normal spinal movements and an inverse analysis is applied to determine the viscoelastic parameters for the spine, based on cadaver test results. The model is further validated using ANSYS dynamic finite element analysis and experimentally validated using a newly designed and fully instrumented whiplash test fixture. Our findings reveal the effectiveness of the simplified model which can be easily scaled to accommodate differences in collision severity, posture, gender, and occupant size.

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.

In this thesis, a highly selective broadband hybrid bandpass filter operating between 0.4-2.0 GHz with a stopband up to 7 GHz is designed and analyzed. The realization is carried out by hybrid method, which combines both lumped and distributed element filters. In this approach, two separate filters, which are lumped highpass with 0.4 GHz corner frequency and distributed stripline lowpass with 2 GHz corner frequency, are combined to get the bandpass filter that has a passband in between 0.4 to 2.0 GHz. The usage of the lumped elements for the highpass filter resulted in a great size reduction compared to distributed element approach. The design software FILPRO&trade / is used to synthesize the trial filters. More than forty filters are synthesized, and among them, the ones that have better properties are chosen for further processes. Optimization, modeling and electromagnetic simulations of the selected lumped and distributed filters are carried out on the software GENESYS&trade / . Distributed filters are also simulated using the software SONNET&trade / . After the simulations, all of the simulated filters are realized and measured, and the level of consistency with the simulations is observed. According to the results of the measurements, the filter combination that has the best combination of low insertion loss, small dimensions, high stopband attenuation and low spur levels is selected for the final bandpass filter structure and a few variants are examined to get the final structure.