Artificial Magnetic Materials Using Fractal Hilbert Curves
ABSTRACT Novel configurations based on Fractal Hilbert curves are proposed for realizing artificial magnetic materials. It is shown that the proposed configuration gives significant rise to miniaturization of artificial unit cells which in turn results in higher homogeneity in the material, and reduction in the profile of the artificial substrate. Analytical formulas are proposed for design and optimization of the presented structures, and are verified through full wave numerical characterization. The electromagnetic properties of the proposed structures are studied in detail and compared to square spiral from the point of view of size reduction, maximum value of the resultant permeability, magnetic loss, and frequency dispersion. To validate the analytical model and the numerical simulation results, an artificial substrate containing second-order Fractal Hilbert curve is fabricated and experimentally characterized using a microstrip-based characterization method.
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ABSTRACT: The effective permeability in a resonance situation becomes a big issue whenever it has to be negative in a metamaterial resonator. This permeability is a measure of magnetic polarization in response to a magnetic field. By using the Biot–Savart law, in this study, the magnetic field distributions inside a loop in resonance/nonresonance situations are theoretically analyzed and then simulated using a 3D electromagnetic tool. We employed a simple analytic model that considers the losses on a metallic loop. Through the exploration of the magnetic field distributions, this paper provides physical insights into the resonance mechanisms of a metamaterial resonator. The dissimilar aspects occurring in resonance and nonresonance situations are discussed in detail.Journal of Electromagnetic Waves and Applications 01/2013; 27(1):30-38. DOI:10.1080/09205071.2012.737909 · 1.40 Impact Factor
Conference Paper: Improved Analytical Model for Short-wire Metamaterials[Show abstract] [Hide abstract]
ABSTRACT: Short wire metamaterial is a kind of metamaterial, which has a very simple manufacturing process. In spite of regular metamaterials whose fabrication requires compressing and stacking of several printed circuit boards (PCBs), short-wire metamaterials can be fabricated using standard multi-layer PCB fabrication. These metamaterials have already been introduced and modeled; however, the reported analytical models have a big deviation from simulation and measurement results. Here; we propose an accurate analytical model for prediction of the resonant frequency of these metamaterials. The analytical model has been verified through comparison with previously reported measurement results.The 5th International Conference on Metamaterials, Photonic Crystals and Plasmonics, SINGAPORE; 05/2014
Conference Paper: A probe for detecting magnetostatic surface resonant spheres[Show abstract] [Hide abstract]
ABSTRACT: We propose a novel probe for detecting magnetostatic surface resonant spheres. The probe is composed of a two-loop resonator in which the inner loop is loaded with a capacitor whose value can be adjusted to achieve probe resonance at desired frequency. This probe produces substantial variation in its reflection coefficient in presence of a magnetostatic resonant sphere with negative real permeability, whereas non-resonant spheres do not yield any significant effect. The mechanism behind this is explained and can be generalized to detect magnetostatic resonant spheres in low microwave frequencies. Probe design is presented along with full-wave numerical simulations.2013 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting; 07/2013