Simulation d’un Circulateur Coplanaire Passif Ayant un Conducteur Central Triangulaire avec une Couche Mince d’Hexaferrite de Baryum Dans la Bande 10-20Ghz

Cet article présente la conception et l'analyse d'une nouvelle structure triangulaire d’un circulateur coplanaire dans la gamme de fréquences de 10 à 20 GHz. Le matériau magnétique utilisé dans ce circulateur est un hexaferrite de baryum avec une faible aimantation de saturation. Les simulations ont été effectuées avec le logiciel HFSS d’Ansoft qui utilise la méthode des éléments finis pour calculer numériquement les paramètres S du circulateur

Improved Transmission Waveguide Bends in Photonic Crystal

A major drawback of conventional dielectric waveguides is that their bending radii are limited to several millimeters due to the degradation of total internal reflection. Since the guiding of light in a PhC defect waveguides is not given through total internal reflection but the photonic bandgap (PBG) effect they can provide bending within the subwavelength range. Hence, PhC waveguides offer a promising scheme for low loss and ultra-dense optical integration. In this paper we have investigated and optimized 60° and 90° waveguides bends that are implemented in a planar photonic crystal (PhC) with triangular and square lattice symmetry. The in-plane guiding within the planar PhC structure is based on a W1 defect waveguide (a single line defect acting as a light channel in the Γ-K-direction) whereas for the vertical light confinement we rely in a slab waveguide formed by the low index contrast material system InGaAsP/InP. To achieve a reasonable band-gap around 1.55 μm the PhC consists of a lattice of holes with a filling factor of 39%. Key optical design parameters are characterized using 2D Finite difference time domain (FDTD) solution of the full-Wave Maxwell's equations. We show a significant improvement in both the transmission efficiency (up to 97%) and the transmission bandwidth by performing an optimization based on a sensitivity analysis