Design of harmonic-tuned dual-band GaN HEMT power amplifier based on genetic algorithm

The design of a harmonic-tuned dual-band GaN HEMT power amplifier (1.28 GHz and 2.14 GHz) is presented. The transistor´s load impedance at the fundamental frequency, the second and third harmonics in both pass-bands were optimally selected to increase the output power and efficiency. In order to design an output matching network from these data, a new CAD procedure has been used that is implemented by means of the genetic-algorithm-based software for automatic synthesis of passive networks. This allows facilitating and accelerating the network design significantly. The measured performances of the dual-band amplifier are as follows: P_out = 37.28 dBm, G = 11 dB, PAE = 42.1% at f₁ = 1.28 GHz; P_out = 35.7 dBm, G = 9 dB, PAE = 23.7% at f₂ = 2.14 GHz.