Characterizing waveguide open and slit coupled T-junctions using single port mode matching technique

A novel rigorous method, called the single port mode matching technique (SPMMT), for modeling rectangular waveguide T-junctions is described. Using mode matching the method computes the reflection coefficient in port 3 (the side arm) with both ports 1 and 2 shorted. The complete 3-port scattering matrix of the T-junction is obtained from nine reflection coefficient computations using different short-circuit lengths in ports 1 and 2. This method reduces the computational effort significantly and can be applied to various structures. Both open and slit coupled T-junctions are analyzed, and the results are in good agreement with experimental measurements.<>