Confusion with derivation of average power formula
I found the issue, thanks to your comments.  In my power course, the voltage phasor is defined as having RMS magnitude \$ V_{max} / \sqrt2 \$, while in my RF course, the voltage phasor is defined as having magnitude \$ V_{max} \$, where \$ v(t) = V_{max}cos(wt + \theta_v) \$.  So in my RF course, complex power would actually equal \$ (1/2)VI^* \$.  Therefore, \$ (1/2)Re(2S) = P \$.