Hi, wlcsp:
There are two conditions there:
1. A_left and A_right are symmetrical
2. A_left and A_right are identical.
If any of the 2 conditions is not met, you will not have a unique solution mathematically. From the A_measured and A_thru, you will not be able to find the A_left and A_right and A_microstrip.
You mentioned the 1st scheme. Do you mean the scheme using EM simulation results? Free IE3D evaluation license is available on the web (
www.zeland.com). Thanks!