Domain decomposition FDTD algorithm combined with numerical TL calibration technique and its application in parameter extraction of substrate integrated circuits
A novel synthetic transmission line and its coupling structure are shown in this paper. By connected strips in different layers with periodic metallic vias, it provides a stronger coupling with effective broad-side than conventional edge coupling. This paper presented the analysis method and the design process of directional coupler. A broadband directional coupler with three-sections is designed and measured.