If you want to get Power Added Efficiency in ADS using HB simulation, you should do these steps:
1. put P_Probes (power probes) from probe pallette at input and output of your PA schematic with names for example P_Out for output and P_In for input.
2. use a frequency source i.e. P1_tone. at input and define a variable for input power so you can sweep that.
3. simulate the design.
4. at data display sheet, create an equation and write PAE equation. don't forget to calculate DC power from your bias variables (using p_probe or i_probe)