Rigorous Mode Matching Method for Circular to Off-Centre-Rectangular Side-Coupled Waveguide Junctions

An accurate and efficient method for analyzing circular to multiple off-center rectangular side-coupled waveguide T-junctions is developed based on a rigorous Mode Matching technique. The method is very general and not limited by symmetry or other dimensional constrains to the junction. The new way to match field on the curved interface between subregions is described in detail. The computer code developed based on this theory is highly efficient. The numerical results match with the measured results as well as the results obtained by other methods.