fresnel zone plate antenna (fzpa) was considered as a recieving antenna. an expression of electric field on axis of antenna produced by an incidente plane wave was found . the expression was used for calculation of gain, efficiency and optimum phase correcting function. several fzpa are fabricated and tested. experimental and theoretical results were compared and it was shown that there was a g...

Introduction. The generation of magnetic resonance images with waveguides has been successfully demonstrated at 7 Tesla for whole-body systems. [1]. It has been previously shown published by our group that the waveguide approach can be used at 3T and whole-body systems using a parallel-plate waveguide [2]. The parallel-plate waveguide is probably the simplest waveguide available and its electro...

P A P ER Abstract Metamaterials offer exciting opportunities that enable precise control of light propagation, its intensity and phase by designing an artificial medium of choice. Inducing birefringence via engineered metamolecules presents a fascinating mechanism to manipulate the phase of electromagnetic waves and facilitates the design of polarimetric devices. In this paper, a high-efficienc...

Earth’s upper mantle includes a 200 km thick asthenosphere underneath the plates where viscosity and seismic velocities are reduced compared to the background. This zone of weakness matters for plate dynamics and may be required for the generation of plate tectonics itself. However, recent seismological and electromagnetic studies indicate strong heterogeneity in thinner layers underneath the p...

The time–harmonic electromagnetic responses of (a) a bilayer made of an epsilon–negative layer and a mu–negative layer, and (b) a single layer of a negative phase– velocity material are compared. Provided all layers are electrically thin, a restricted equivalence between (a) and (b) exists. The restricted equivalence depends on the linear polarization state and the transverse wavenumber. Implic...

The time–harmonic electromagnetic responses of (a) a bilayer made of an epsilon–negative layer and a mu–negative layer, and (b) a single layer of a negative phase– velocity material are compared. Provided all layers are electrically thin, a restricted equivalence between (a) and (b) exists. The restricted equivalence depends on the linear polarization state and the transverse wavenumber. Implic...