Re: Negative power flow for dipole in free space?

The quantity emw.Poavz is derived from the RF fields. You are attempting to evaluate it at the center of your dipole, and whether that is a physically-meaningful location is highly-questionable. Even so, the z-component of the average power flow there should evaluate to zero anyway, since the radiated field of a dipole along the z-axis has a null on the z-axis. I'm guessing that you are merely seeing numerical noise.