The effect of 2nd harmonic control on power amplifiers performances

This contribution is aimed to study the effects of 2nd harmonic control on power amplifiers. Two different power amplifiers employing 2nd harmonic terminations are examined and compared to each other. In order to give an evidence of the theory, a couple of hybrid power amplifiers in GaN technology, a 2nd harmonic manipulated PA and a Class J PA, are designed at 3 GHz of center frequency and compared to each other. Preliminary results give better efficiency (more than 55%) but narrower bandwidth (less than 300 MHz) for the 2nd harmonic tuned PA, demonstrating the inherent tradeoff at the base of power amplifier design.