polarization conversion efficiency in CST MWS

I have a question about circular polarization analysis in CST MWS. I would like to simulate a structure in optical regime which converts from linear to circular polarization light. In some papers the authors evaluate the conversion (from linear to circular) efficiency by CST MWS.
Do you think they use the the axial ration calculated by a farfield monitor to obtain it?
Could you hint me a post-processing method or function for it?

申明：网友回复良莠不齐，仅供参考。如需专业解答，请学习易迪拓培训专家讲授的CST视频培训教程。