@article{SydorukShamoninChamonineRadkovskayaetal., author = {Sydoruk, O. and Shamonin (Chamonine), Mikhail and Radkovskaya, A. and Zhuromskyy, O. and Shamonina, Ekaterina and Trautner, Ralph and Stevens, C. J. and Faulkner, Grahame and Edwards, David J. and Solymar, L.}, title = {Mechanism of subwavelength imaging with bilayered magnetic metamaterials: Theory and experiment}, series = {Journal of Applied Physics}, volume = {101}, journal = {Journal of Applied Physics}, number = {7}, publisher = {AIP}, doi = {10.1063/1.2714782}, abstract = {We present a theoretical and experimental study of a bilayered metamaterial structure for subwavelength imaging of magnetic field. The simplest version of such a structure consists of one or two linear arrays of capacitively loaded split pipe resonators. Its subwavelength physics is governed by strongly anisotropic magnetic coupling between individual resonators and by propagation of magnetoinductive waves with wavelength much shorter than the wavelength of the electromagnetic radiation in free space. It is shown that magnetoinductive waves propagating in the lateral direction are undesirable because they spread the image. Good subwavelength imaging is achieved when, due to the strong interlayer coupling, a stop band in the vicinity of the resonant frequency appears in the dispersion characteristics. The imaging properties of the single and double lens are compared and it is shown that the double lens has a superior performance. Excellent agreement is obtained between experimental and theoretical results for the magnetic field in the image plane in the operation frequency range of 30-60 MHz. It is shown that the same mechanism is responsible for image formation using bilayered planar metamaterial structures and a design of such a lens comprising two planar layers with a total of 542 elements is provided. The conclusions are not restricted to the radio frequency region because the elements can be scaled down.}, language = {en} } @article{SydorukRadkovskayaZhuromskyyetal., author = {Sydoruk, O. and Radkovskaya, Anna A. and Zhuromskyy, Oleksandr and Shamonina, Ekaterina and Shamonin (Chamonine), Mikhail and Stevens, Chris J. and Faulkner, Grahame and Edwards, David J. and Solymar, L.}, title = {Tailoring the near-field guiding properties of magnetic metamaterials with two resonant elements per unit cell}, series = {PHYSICAL REVIEW B}, volume = {73}, journal = {PHYSICAL REVIEW B}, number = {22}, publisher = {APS}, doi = {10.1103/PhysRevB.73.224406}, abstract = {A theoretical and experimental study of magnetic metamaterials with unit cells containing two resonant elements is presented. The properties of these structures, consisting of split rings, are governed by strongly anisotropic magnetic coupling between individual elements. This coupling leads to propagation of slow magnetoinductive waves in the vicinity of the resonant frequency. The wavelength of magnetoinductive waves is much smaller than the free-space wavelength of the electromagnetic radiation. This opens up the possibility of manipulating the near field on a subwavelength scale. We develop a theoretical formulation for coupled chains of metamaterial elements allowing the tailoring of their guiding properties in the near field. In a comprehensive analysis modes of coupled waveguides supporting forward and/or backward waves are identified and the corresponding hybridization mechanisms for dispersion equations of magnetoinductive waves are determined. Analytical predictions are verified both experimentally and numerically on a variety of coupled waveguides. The approach can be employed for the design of near-field manipulating devices.}, language = {en} }