13.56MHz Class E power Amplifer

hi , anyone has idea on how to simulate a class e power amplifier efficiency working with 13.56Mhz frequency, using ADS?

attention should be paid to the Vout/Vin or power efficiency or just the S paramters?

what is the transistor

hi,

the transistor is irf510.
vgs is min 2V and max 4V at room temp. the Vgs maximum threshold is +-20V