How to get the antenna electric field of far field

[RFbeginner]

surface electric field on antenna is known, how to get the antenna electric field of far field, it is said that, we should use dyadic Green functions, I don't know the detailed process, plese give me some advice.
Thanks in advance.

 

[savedadogs]

I think you need the tangential electric field, but after that I am not so sure...I know you can not use the regular Green's function since it requires you to know both the tangential E and H fields. Have you looked at the book Advanced Electromagnetics by Balanis? I think he has a small chapter descibing the dyadic Green's function.