The performance of this class-E amplifier is first measured under the initially designed conditions. The drain dc supply voltage is 15 V; the gate dc bias voltage is selected to be 3.3 V, which is just above the turn-on threshold of the transistor. In the measurements, this amplifier offers an output power of 36.2 dBm (4.17 W), drain efficiency of 83.6%, PAE of 82.6%, and 19.2-dB gain at an input power level of 17 dBm. The measured and simulated results of the output power, drain efficiency and gain of this amplifier as a function of input power are shown in Fig. 8. The results show that the measured and simulated results match well under the same conditions.