STUDYING ELECTROMAGNETIC WAVE-GUIDING AND RESONATING DEVICES

摘要: Various electromagnetic wave-guiding and resonating structures are studied. The in question rather complicated thus, significant part of the used analysis methods numerical. Numerical field computation is based on finite-difference method (FD) or time-domain (FDTD). When possible, analytical have been used, often conjunction with numerical computation. Most structures, if not all, find real-life applications. Thus, focus has much such issues as fluency structure design quickness analysis. Firstly, combline-filter investigated. These components widely mobile communication devices, radio-frequency microwave regime, for example. A semianalytic method, which multiconductor-transmission-line theory 2-D via FD found very efficient. Computationally costly 3-D avoided. This speeds up process combline filters. Secondly, so-called hard-surface-waveguide analytically approximating longitudinally corrugated waveguide wall an ideal hard surface, one can concentrate effects caused by media inside tube. First component filled uniaxial anisotropic medium. For this structure, be a polarisation transformer, solutions transmitted reflected field, especially helicity field. Second gyrotropic medium, electrically controllable ferrite case. mode example, from TM to TE mode. Analytical fields. Finally, photonic-bandgap (PBG) material kind periodically inhomogeneous also known photonic crystal (PhC), having ability inhibit propagation wave crystal. Carefully designed PBG may several applications, integrated optics. In thesis, triangular lattice air holes etched through dielectric background. Further, bends special interest, partly because they give chance realising tight light-channel related FDTD discussed. importance PBG-component optimisation demonstrated. Promising results obtained extremely bends, although radiation losses real recognized problem. Some basic components, 60 120 degree taper, designed.