setting Axial ratio graph in cst

Hi....i want to know the right setting of axial ratio in CST...

i have seen different setting for axial ratio from different papers...so, it make me confuse which one is the right one...

1) theta 90, min value

2) theta 0,phi 90

(both 2 pictures are from template based processing result in cst)

so, which one is right? and setting for coordinate (for Circular Polarization) should be spherical or ludwig3?

thanks