Based On Coplanar Waveguide Improve Fdtd Electromagnetic Properties Calculation And Testing Methods

Coplanar waveguide, a kind of surface strip transmission line attracts more and more attention because of its excellent performance. Many researches of coplanar waveguide are based on the ideal condition. However, coplanar waveguide can not be ideal in real microwave circuits, and it has great effect on its electromagnetic characteristics. So it is necessary to research the coplanar waveguides under the non-ideal circumstances.FDTD is suitable for investigating surface strip transmission line among all methods, due to advantages which information in wide frequency spectrum could be obtained by single time-domain calculation. FDTD was chosen as the research method in this thesis, and electromagnetic characteristics of coplanar waveguide with different ground plane width have been analyzed. Both FDTD and ADI-FDTD were used in this simulation process, and they were implemented in Matlab and C environment. The characteristics impedance, effective dielectric constants and propagation constants were calculated and compared with the experiment results. The effects on the electromagnetic characteristics of coplanar waveguide with different ground plane width were presented.In this thesis, principles and process of FDTD analyzing on coplanar waveguides were presented. Coplanar waveguide was modeled and subgridding grids technique was applied to the analysis of coplanar waveguide. Subgridding grids ware used in the area where electromagnetic field change incentively, and normal grids are used in others, CPU time was reduced obviously with satisfied precision by this approach. Gedney perfect match layer was adopted as absorbing boundary in the simulation, avoid magnetic field breaking up in the absorbing medium, and memory requirement was reduced and programming became easier.Finally, the whole work of this thesis was concluded and the think of next step work were presented.