problems with coaxial feed using cst and generating worried S parameter ! !

Hello!
I am simulating a micro-strip patch antenna, this is one of my first steps in using the coaxial feed, I am following the tutorial to do so but I am getting a worried S parameter plot. How can I explain it?!
Note: I am attaching the cst file and the S plot, hope you can help me ?
Many thanks
NewFile.rar