Analysis of a cylindrical coupling structure

Coupled lines perpendicular to their cylindrical ground plane embedded in a cylindrical structure are proposed and analyzed CAD-oriented analytic form ulas for investigating the quasistatic mode parameters and the coupling pro perties are derived with the even-odd mode analysis method based on the qua si-TEM approximation. Calculated mode impedances and coupling coefficients are observed to be sensitive to cylindrical curvature, especially for large r values of the spacing in the ground plane. Calculated results are compare d,vith those obtained for a corresponding planar coupling structure. (C) 19 99 John Wiley & Sons, Inc.