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Yes / A shared ground shared radiator with wide angular coverage for mmWave 5G smartphones is proposed in this paper. A four-element corporate-fed array with conventional impedance matched power divider is designed. Stepped impedance transformers are integrated with the corner most elements to achieve pattern diversity with wide angular coverage without signifi-cant compromise in gain. The proposed three-port shared radiator conformal commercial an-tenna could be easily integrated with commercial mmWave 5G smartphones. All the three ports’ excitations operate in the 28 GHz band. Radiation pattern bandwidth of the multi-port system is high. The gain variation is from 6 to11 dBi amongst the ports and across the operating spectrum. The highest mutual coupling is 10 dB, in spite of the electrically connected structure. The pro-posed shared radiator element has a wide angular coverage of 100°, maintaining high front-to-back ratio when the respective port is excited. Simulation and measurement results for the proposed structure are illustrated in detail. / This work is supported by the Moore4Medical project, funded within ECSEL JU in collaboration with the EU H2020 Framework Programme (H2020/2014-2020) under grant agreement H2020-ECSEL-2019-IA-876190, and Fundação para a Ciência e Tecnologia (ECSEL/0006/2019).

Methods featured are primarily conformal symplectic exponential time differencing methods, with a focus on families of methods, the construction of methods, and the features and advantages of methods, such as order, stability, and symmetry. Methods are applied to the problem of the damped harmonic oscillator. Construction of both exponential time differencing and integrating factor methods are discussed and contrasted. It is shown how to determine if a system of equations or a method is conformal symplectic with flow maps, how to determine if a method is symmetric by taking adjoints, and how to find the stability region of a method. Exponential time differencing Stormer-Verlet is derived and is shown as the example for how to find the order of a method using Taylor series. Runge-Kutta methods, partitioned exponential Runge-Kutta methods, and their associated tables are introduced, with versions of Euler's method serving as examples. Lobatto IIIA and IIIB methods also play a key role, as a new exponential trapezoid rule is derived. A new fourth order exponential time differencing method is derived using composition techniques. It is shown how to implement this method numerically, and thus it is analyzed for properties such as error, order of accuracy, and structure preservation.

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Consumer additive manufacturing (3D printing) has rapidly grown over the last decade. While the technology for the most common type, Fused Filament Fabrication (FFF), has systematically improved and sales have increased, fundamentally, the capabilities of the machines have remained the same. FFF printers are still limited to depositing layers onto a flat build plate. This makes it difficult to combine consumer AM with other objects. While consumer AM promises to allow us to customize our world, the reality has fallen short. The ability to directly modify existing objects presents numerous possibilities to the consumer: personalization, adding functionality, improving functionality, repair, and novel multi-material manufacturing processes. Indeed, similar goals for industrial manufacturing drove the research and development of technologies like direct write and directed energy deposition which can deposit layers onto uneven surfaces. Replicating these capabilities on consumer 3-axis FFF machines is difficult mainly due to issues with reliability, repeatability, and quality. This thesis proposes, demonstrates, and tests a method for scanning and printing dimensionally-accurate (unwarped) digital forms onto physical objects using a modified consumer-grade 3D printer. It then provides an analysis of the machine design considerations and critical process parameters. / Master of Science / Consumer additive manufacturing (3D printing) has rapidly grown over the last decade. While the technology for the most common type, Fused Filament Fabrication (FFF), has systematically improved and sales have increased, fundamentally, the capabilities of the machines have remained the same. FFF printers are still limited to depositing layers onto a flat build plate. This makes it difficult to combine consumer AM with other objects. While consumer AM promises to allow us to customize our world, the reality has fallen short. The ability to directly modify existing objects presents numerous possibilities to the consumer: personalization, adding functionality, improving functionality, repair, and novel multi-material manufacturing processes. Indeed, similar goals for industrial manufacturing drove the research and development of technologies like direct write and directed energy deposition which can deposit layers onto uneven surfaces. Replicating these capabilities on consumer 3-axis FFF machines is difficult mainly due to issues with reliability, repeatability, and quality. This thesis proposes, demonstrates, and tests a method for scanning and printing dimensionally-accurate (unwarped) digital forms onto physical objects using a modified consumer-grade 3D printer. It then provides an analysis of the machine design considerations and critical process parameters.

This thesis investigates the performance of a phased array of antenna elements conforming to a paraboloidal surface. We hypothesize that such a conformal phased array would have performance comparable to that of a correspondingly sized planar array. The performance of a paraboloidal array of antenna elements was simulated using an array program, and the resulting gains, side-lobe levels, and half-power beamwidths compared to those of a similarly sized planar array. Furthermore, we propose a beam-forming feed network for this paraboloidal phased array, and discuss the influence that coupling between the elements could have on the array performance. Lastly, we propose that such an array be used in conjunction with a parabolic reflector antenna to form a versatile hybrid antenna with several potential applications. / Master of Science