Two-dimensional finite difference time domain analysis of cylindrical transmission lines

Recently, there has been a growing interest in the use of cylindrical trans mission lines in a variety of applications. In this paper, the finite diffe rence time domain (FDTD) method is used to calculate the propagation charac teristics of cylindrical transmission lines. An efficient two-dimensional ( 2D) FDTD algorithm is developed by projecting the three-dimensional FDTD ce ll in the cylindrical coordinates on to the r-phi plane. An effective absor bing boundary condition is employed to truncate the mesh at its outer radia l boundary. In addition to a detailed description of the developed 2D-FDTD algorithm, extensive numerical results are derived for different cylindrica l transmission lines and compared with data available in the literature. Sp ecifically, the newly proposed cylindrical coplanar waveguide is studied bo th theoretically and experimentally.