I guess that the element does not have the same response for s and p polarization, thus it can be difficult to have ONE S parameter to quantify the result. Due to limited access to the pulications, I do not have any idea how to extract the usful information when the two polarized sources are used, either at the same time or independently. Please search some publication and find a method to quantify such result in order to optimize. This may need more theoretical analysis than simulation. You can use two sources independently and then you get two different S values. You will need to combine them into one value somehow.
There is no such exmaple on line right now.
You are navigating away from the AIS Discovery experience