This paper presents a new topology to implement Class F power amplifier for eliminating the on - resistance ( RON ) effect. The time-domain and frequency-domain voltage and current waveforms for Class F amplifier are analyzed using Fourier series analysis method. Considering the on-resistance effect, the formulas of the efficiency, output power, dc power dissipation, and fundamental load impedance are given from ideal current and voltage waveforms. For experimental verification, we designed and implemented a Class F power amplifier, which operates at 850 MHz using AlGaAs/GaAs Heterostructure FET (HFET) device, and analyzed the measurement results. Test results show that the maximum PAE of 67% can be achieved at 28 dBm output power level.