A 3.3 GHz class-E power amplifier with 77% PAE utilising GaN HEMT technology

High efficiency with high power amplification is of great concern in modern wireless communication systems to increase battery life and reliability. GaN Heterojunction Electron Mobility Transistors (HEMT) have found widespread applications in RF/microwave power amplifiers (PAs) to fulfill these requirements. In this paper, a transmission-line based class-E PA is designed in GaN HEMT technology at 3.3 GHz. The implemented load transformation network (LTN) of the PA separates the DC biasing and the second harmonic termination into two sections as compared to conventional LTN for class-E PAs to attain high efficiency. Measured impedances of the passive LTN are in good agreement with the desired values. Measurement results of the class-E PA show peak power added efficiency (PAE) of 76.9% and peak output power of more than 38.0 dBm, when operated from a 28V supply.