Abstract: In this paper, a high efficiency Class-E-1 / F RF power amplifier (PA) based on 5G frequency band is proposed using GaN HEMT. In order to reduce the influence of the parasitic parameters and higher harmonics of the transistor on the switching performance and output characteristics of the Class-E-1 PA, the Class-F-1 PA harmonic control network with parasitic parameter compensation is introduced into the output power matching circuit of the Class-E-1 PA, to realize the open circuit and the short circuit processing for the second harmonic and the third harmonic respectively, so as to make the Class-E-1 PA possess good switching characteristics. Besides, due to the good performance of harmonic control of the Class-F-1 PA, the ideal waveform of the drain output current and voltage are realized which greatly reduced the PA′s drain current and voltage, and the output capability of the PA is improved greatly. The measured results show that in the effective operating bandwidth 300MHz within 3. 3 ~3. 6GHz, the Class-E-1 / F PA has the power added efficiency (PAE) of 59. 1% ~71. 4%, the maximum drain efficiency reaches 75. 6%, the output power is among 40. 2 ~41. 5dBm, and the gain flatness is within ±1dB. Finally, the amplifier is linearized by the generalized memory polynomial (GMP) digital pre-distorter (DPD) and tested by a 20 MHz bandwidth single-carrier LTE signal. The adjacent channel power ratio (ACPR) of the amplifier output is improved by nearly 15dB.