A high efficiency VHF GaN HEMT class E power amplifier for public and homeland security applications

Power efficiency is a very important specification of power amplifiers for mobile and wireless communication systems. High power efficiency leads to long lasting connection time for mobile, nomadic and wireless devices using battery energy. Especially for public and homeland security applications, long connection time of wireless communication devices is desirable for emergency situations. This paper proposes a high efficiency class E power amplifier with a Gallium Nitride High Electron Mobility Transistor (GaN HEMT) as a power device. A parallel load circuit is used in this class E power amplifier which operates in the frequency range of 140-170 MHz. Furthermore, load-pull technique was applied during the design process to determine the optimal load impedance for the maximum Power-Added Efficiency. Simulation and measurement results of the fabricated class E power amplifier are provided with a peak Power-Added Efficiency (PAE) of 72.5% and power gain of 16.4 dB at 33.9 dBm output power.