Artificial Magnetic Materials (AMMs) are a subgroup of metamaterials which are engineered to provide desirable magnetic properties not seen in natural materials. These artificial structures are designed to provide either negative or enhanced positive (higher than one) relative permeability. AMMs with negative permeability are used to develop Single Negative (SNG), or Double Negative (DNG) metamaterials. AMMs with enhanced positive permeability are used to provide magneto-dielectric materials at microwave frequencies where the natural magnetic materials fail to work efficiently. AMMs are realized by embedding metallic resonators in a host dielectric. These inclusions provide desirable magnetic properties near their resonance frequency. Artificial magnetic materials used as SNG, or DNG have many applications such as: sub-wavelength cavity resonators, sub-wavelength parallel-plate wave guides, sub-wavelength cylindrical and spherical core–shell systems, efficient electrically small dipole antennas, super lenses, THz active devices, sensitivity enhancement near-field probes using double and single negative media, and mutual coupling reduction between antennas. On the other hand, artificial magnetic materials used as magneto-dielectrics have other applications in developing enhanced bandwidth efficient miniaturized antennas, low profile enhanced gain antennas using artificial magnetic superstrates, wide band woodpile Electromagnetic Band Gap (EBG) structures, EBGs with enhanced in-phase reflection bandwidth used as artificial magnetic ground planes. In this thesis, several advances are added to the existing knowledge of developing artificial magnetic materials, in terms of analytical modeling, applications, realization, and experimental characterization. To realize AMMs with miniaturized unit cells, new inclusions based on fractal Hilbert curves are introduced, and analyzed. Analytical models, numerical full wave simulation, and experimental characterization are used to analyze, and study the new structures. A comprehensive comparison is made between the new inclusions, and perviously developed inclusions in terms of electromagnetic properties. The new inclusions have advantages of miniaturization, and less dispersion when compared to the existing structures in the literature. To realize multi-band AMMs, unit cells with multiple inclusions are proposed, designed, and analyzed. The new unit cells can be designed to give the desired magnetic properties either over distinguished multiple frequency bands, or over a single wide frequency band. Numerical full wave simulation is used to verify the proposed concept, and analytical models are provided for design, and optimization of the new unit cells. Unit cells with different configurations are optimized to get a wideband responce for the effective permeability. Space mapping technique is used to provide a link between analytically optimized structures, and full wave numerical simulation results. Two new methods are proposed for experimental characterization of artificial structures using microstrip, and strip line topologies. Using numerical results, the effect of anisotropy on the accuracy of the extracted parameters are investigated, and a fitting solution is proposed, and verified to address this challenge. New structures based on 2nd , and 3rd order fractal Hilbert curves are fabricated, and characterized using microstrip line, and strip line fixtures. Experimental results are presented, and compared with numerical results. The new experimental methods have advantages of lower cost, easier to fabricate and measure, and smaller sample size when compared to the existing methods in the literature. A new application is proposed for use of magnetic materials to develop wide band artificial magnetic conductors (AMC). Analytical models, and numerical analysis is used to validate the concept. A new ultra wideband AMC is designd, and analysed. The designed AMC is used as the ground plane to develop a low profile high gain ultra wide band antenna. The designed antenna is simulated, and its return loss, and gain is presented over a wide range of frequencies. A comprehensive study is presented on the performance of AMMs for the application of miniaturized antennas. A miniaturized antenna, using fractal Hilbert metamaterials as substrate, is fabricated, and measured. Measurement results are presented, and compared with numerical results. A parametric study is presented on the effect of the constitutive parameters of the artificial substrate on the performance of the miniaturized antenna. In this study, the effect of magnetic loss of AMM on the gain, and efficiency of the antenna, as well as the effect of dispersion of AMM on the bandwidth of the antenna is investigated.

Artificial Magnetic Materials (AMMs) are a subgroup of metamaterials which are engineered to provide desirable magnetic properties not seen in natural materials. These artificial structures are designed to provide either negative or enhanced positive (higher than one) relative permeability. AMMs with negative permeability are used to develop Single Negative (SNG), or Double Negative (DNG) metamaterials. AMMs with enhanced positive permeability are used to provide magneto-dielectric materials at microwave frequencies where the natural magnetic materials fail to work efficiently. AMMs are realized by embedding metallic resonators in a host dielectric. These inclusions provide desirable magnetic properties near their resonance frequency. Artificial magnetic materials used as SNG, or DNG have many applications such as: sub-wavelength cavity resonators, sub-wavelength parallel-plate wave guides, sub-wavelength cylindrical and spherical core–shell systems, efficient electrically small dipole antennas, super lenses, THz active devices, sensitivity enhancement near-field probes using double and single negative media, and mutual coupling reduction between antennas. On the other hand, artificial magnetic materials used as magneto-dielectrics have other applications in developing enhanced bandwidth efficient miniaturized antennas, low profile enhanced gain antennas using artificial magnetic superstrates, wide band woodpile Electromagnetic Band Gap (EBG) structures, EBGs with enhanced in-phase reflection bandwidth used as artificial magnetic ground planes. In this thesis, several advances are added to the existing knowledge of developing artificial magnetic materials, in terms of analytical modeling, applications, realization, and experimental characterization. To realize AMMs with miniaturized unit cells, new inclusions based on fractal Hilbert curves are introduced, and analyzed. Analytical models, numerical full wave simulation, and experimental characterization are used to analyze, and study the new structures. A comprehensive comparison is made between the new inclusions, and perviously developed inclusions in terms of electromagnetic properties. The new inclusions have advantages of miniaturization, and less dispersion when compared to the existing structures in the literature. To realize multi-band AMMs, unit cells with multiple inclusions are proposed, designed, and analyzed. The new unit cells can be designed to give the desired magnetic properties either over distinguished multiple frequency bands, or over a single wide frequency band. Numerical full wave simulation is used to verify the proposed concept, and analytical models are provided for design, and optimization of the new unit cells. Unit cells with different configurations are optimized to get a wideband responce for the effective permeability. Space mapping technique is used to provide a link between analytically optimized structures, and full wave numerical simulation results. Two new methods are proposed for experimental characterization of artificial structures using microstrip, and strip line topologies. Using numerical results, the effect of anisotropy on the accuracy of the extracted parameters are investigated, and a fitting solution is proposed, and verified to address this challenge. New structures based on 2nd , and 3rd order fractal Hilbert curves are fabricated, and characterized using microstrip line, and strip line fixtures. Experimental results are presented, and compared with numerical results. The new experimental methods have advantages of lower cost, easier to fabricate and measure, and smaller sample size when compared to the existing methods in the literature. A new application is proposed for use of magnetic materials to develop wide band artificial magnetic conductors (AMC). Analytical models, and numerical analysis is used to validate the concept. A new ultra wideband AMC is designd, and analysed. The designed AMC is used as the ground plane to develop a low profile high gain ultra wide band antenna. The designed antenna is simulated, and its return loss, and gain is presented over a wide range of frequencies. A comprehensive study is presented on the performance of AMMs for the application of miniaturized antennas. A miniaturized antenna, using fractal Hilbert metamaterials as substrate, is fabricated, and measured. Measurement results are presented, and compared with numerical results. A parametric study is presented on the effect of the constitutive parameters of the artificial substrate on the performance of the miniaturized antenna. In this study, the effect of magnetic loss of AMM on the gain, and efficiency of the antenna, as well as the effect of dispersion of AMM on the bandwidth of the antenna is investigated.

Alzheimer’s Disease, also called AD, is a horrible, degenerative brain disease that more than 35 million people over the world have. Today, there is no cure for this disease, only treatments that are temporarily relieving the symptoms. The two proteins that is thought to be the main cause of AD is amyloid β (Aβ) and tau. Previously, people have tried studying Aβ in vivo using green fluorescent protein fusion together with Aβ. However, this is difficult since the aggregation of Aβ will lead to loss of fluorescence. This study aimed to crystallize the fusion protein mNG-A β1-42 and to investigate its properties as a molecular fluorescent Aβ-amyloid specific probe. Dynamic light scattering (DLS) was used to confirm that the majority of the protein was not in the form of soluble aggregates. The DLS experiments were followed by several rounds of crystallization trials. Initial screening and the subsequent narrowing down of potential conditions where mNG-Aβ1-42 could form crystals. Several staining experiments were conducted as well, including staining brain tissue from mouse with both Swedish and Arctic mutation, from human patients with sporadic AD and from human patients with AD with the Arctic mutation. The DLS experiments showed that the protein used in the crystallization experiments mostly consisted of molecular particles of the same radius. However, there was clear evidence of some larger species present that could have been a potential problem for crystallization. Crystallization experiments suggested that PEG 8000 was the most promising precipitant amongst other conditions identified for crystallization of mNG-Aβ1-42. However, the study was ultimately unsuccessful in developing crystals of sufficient high quality for diffraction studies to commence. The staining experiments demonstrated that mNG-Aβ1-42 could bind both by itself and with another amyloid probe, Congo red, and with antibodies in brain tissue from mouse with both Swedish and Arctic mutation, from human patients with sporadic AD and from human patients with AD with the Arctic mutation. In conclusion, several characteristics of mNG-Aβ1-42 were revealed in this study.