For OZ direction one considers a charge distribution  of     of   an   infinite  line   and  other two of  with   reversed  polarities  in  the point z = {-1,1}.

      The potentials are and . Them superposition produces on intervals zÎ(1,+¥) şi zÎ(-¥, -1) the following potential:

 

                     (2)

 

Taking into account those mentioned above and using a new superposition, the residual potential of the T-branch will be:

                                          

            (3)

 and the integral form:

                               (4)

 Green functions for corner are presented by [2]. Finally, the excess capacitance of the corner is presented in equation (5).

                                                  (5)

For a deeper research in practice, bellow are offered [2] a few approximations of the T-branch parameters, excellent formulas for some discontinuities in microstrip configurations being offered by the famous scientist Gupta. The approximations are included in the lumped equivalent circuit model presented in figure 2 for particular conditions of characteristic impedance (Z₀=50W) and substrate (Al₂O₃, e_r=9,9). The inductances of the two arms can be evaluated very similar as in the case of the corner discontinuity.