Multiconductor Planar Transmission-Line Structures for High-Directivity Coupler Applications

The spectral domain technique is used to analyze multiconductor printed transmission-line structures containing layered dielectric substrate. Starting from general analytical formulation a useful modification of the procedure is suggesteti for accurate description of multiconductor interdigitated microstrip circuit with equally dimensioned conductors. Frequency dependent numerical results for some new microstrip and coplanar structures with more than two coupled lines are shown, discussed with respect to high-directivity multiconductor coupler applications.