Improved calculation of thin layer microstrip-slotline interactions using quasi-static images

The mixed potential formulation for multilayered microstrip-slotline structures described in [1] is improved by the use of quasi-static images. These images dominate the near field behavior of the Green´s potential functions, when thin layers are present in the substrate. The dominant quasi-static images are extracted and treated analytically throughout the whole solution process. Numerical results are shown for a coplanar waveguide mitered bend structure with air-bridges and for a multilayered printed circuit board with a burled capacitance layer.