P_1tone parameter question

Hi guys
I am kind of confusing about P_1tome P setting, for example, I set it to polar(dbmtow(-35),0) W, I calculate the voltage should be 5.62 mv. log((5.62*1e-3)^2/100*1000)=-35 dbm. But Ads software give me voltage of 11.24 mv which is double of 5.62. Do I calculate something wrong or I set the software wrong.
Also, what does PAC mean in P_1tone?
Thanks

If you test the voltage of a power source when it's open you will get a signal voltage two times that when it's matched to a load.

so it is not right, right? Basically what I did is to connect a RF signal port to rest of circuit, how can they just double the signal even I set it to be -35dBm, so should I just decrease the signal level to get the correct -35dBm since it does not make sense to double the signal? How do you guys solve this problem in real simulation? Thanks a lot

The power you set in the source will deliver to the load totally without reflection only if the load is conjugate matched to the source impedance. If you want constant input signal voltage you should use voltage source instead of power source.