The propagation of waves supported by capacitively loaded loops is investigated using a circuit model in which each loop is coupled magnetically to a number of other loops. Since the coupling is due to induced voltages the waves are referred to as magnetoinductive (MI) waves. The mathematical formulations are mostly analytical thanks to long standing previous work on the magnetic and electric fields generated by currents flowing in loops. Retardation is neglected, i.e., dimensions of the structure are assumed to be small relative to the free space wavelength. The dispersion relations, derived in the most general case for a tetragonal three-dimensional structure, exhibit both forward and backward waves within a pass band. It is shown that for reproducing the salient features of the waves it is sufficient to take nearest neighbor coupling into account but coupling between loops further away must also be considered if higher accuracy is required. The investigations include that of resonances, conditions for the existence of traveling waves, tolerances, and streamlines of the Poynting vector. Waveguide components, like bends, power dividers and couplers are considered due to the potential applications of the MI waves as magnetic guides. Generality of the results, their possible implications for transverse electromagnetic wave propagation, previous work on similar waves, including the possibility of phase conjugation, are discussed in a separate section.

No abstract

We consider a possibility to create a metamaterial with nonlinear magnetic response in the microwave frequency range. Such a metamaterial is a regular periodic three-dimensional-array of resonant conductive elements with diodes as nonlinear insertions. We calculate the arising quadratic nonlinear susceptibility and show how it is controlled by the properties and arrangement of the structure elements as well as by the type and characteristics of the diode. We discuss the requirements for the diode necessary to optimize the nonlinear response of the proposed metamaterial.

No abstract

No abstract