You can use Harmonic Tuner ( or something like that ) to obtain PAE curves in Cadence ADE Spectre.
I did it long time ago but it ought to have Magnitude and Phase fields to be filled.You may define 2 variables for those fields such as mag_var and phase_var then you sweep those variables in according to Smith Chart limits then you can check PAE. Cadence Spectre has also an utility for that but I have never used it.
Don't forget to place Current Probes at Input and Output Ports and obviously Voltage Supply source.
You know the definition of PAE, so calculate and plot the curves by using Cadence ADE Calculator.