Description:
<jats:title>Abstract</jats:title><jats:p>In this letter, the design, implementation and measurements of a multioctave bandwidth high‐efficiency GaN HEMT power amplifier (PA) based on a novel systematic design methodology are presented. To achieve bandwidth expansion while maintaining a high level of efficiency, the multi‐harmonic bilateral pull technique has been employed to acquire the optimum fundamental and second harmonic impedance regions. Especially, the impedance region of the second harmonic is analyzed to conclude that the second harmonic impedance can be expanded to a resistive‐reactive with complex load impedances. Therefore, multioctave bandwidth can be achieved by combining low‐pass lumped circuit (LC) matching network. For experimental verification, the wideband PA is achieved with a 10‐W GaN device. The measurement results manifest that the implemented PA has a drain efficiency (DE) of 54% to 71% and a saturated output power of 38.2 to 42.3 dBm for the entire intended frequency range between 0.5 to 3.1 GHz with a relative bandwidth of 144.4%, while providing a gain larger than 8.2 dB. Measurement results confirm the theoretical findings.</jats:p>