create dipole source by discrete port

I use CST Microwave to simulate nanoantenna. I try to use discrete port as a dipole source. I want to simulate both electric and magnetic dipole source. How can I do it? How can I know that its electric or magnetic dipole source?

Thanks.

Ideal point source (J&M) is challenging in FDTD, its actually a singularity point, at which the signal magnitude is infinity, however, the integration over such delta function is a finite value. This is very very challenge for differential based solvers. Especially for its near fields, its error is going to be large.