Metamaterials (MMs) are artificial materials that have received attention recently because their built-in features create collective electromagnetic effects that are otherwise impossible, such as negative refraction, and because of their exotic electromagnetic applications, namely, perfect lens and invisibility cloaks. Depending on wave propagation characteristics, MMs possessing normally weak magneto-electric coupling coefficients start to exhibit stronger bianisotropic effects. Therefore, accurate electromagnetic characterization of these MMs is important. In this study, we adapt a stepwise method based on the Nicolson-Ross-Weir technique for accurate and unique retrieval of electromagnetic properties of bianisotropic MM slabs. For this goal, we have derived explicit expressions for unique retrieval of electromagnetic properties of these slabs and compared these expressions with those in the literature in the retrieval process. From the comparison, we note that derived expressions are appropriate for unique determination of electromagnetic properties of bianisotropic MM slabs. In the performance analysis of the stepwise method for different measurement scenarios, we considered different bianisotropic MM cell configurations (split-ring and Omega-shaped resonators as well as the same resonators with wire strips) and extracted their electromagnetic properties when measured/simulated scattering parameters have some thermal noise. We note that for most of the frequencies, the stepwise method retrieves correct electromagnetic properties even when a relatively higher normally distributed noise with zero mean value and with standard deviations of 0.015 is present. In addition to the influence of thermal noise on performance of the stepwise method, we also analyzed the effect of both increasing length slab and the frequency band on retrieved electromagnetic properties of the analyzed various bianisotropic MM slabs.

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Measurements of Kβ/Kα intensity ratios in elements with 22⩽Z⩽69 have been carried out by stimulating the emission of K characteristic radiation by 59.5 keV monochromatic photons. The x-rays were measured using a Si(Li) detector (160 eV FWHM at 5.9 keV). The experimental results were compared with other theoretical and experimental values.

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