High efficiency and wide band CLASS-J power amplifier using 2nd harmonic microstrip stub matching

This paper proposes a novel and easily-implemented method for Class-J power amplifiers. The 2nd harmonic impedance matching networking is designed and realized by using microstrip stub networks. To prove the concept, a PA prototype operating at the frequency range from 1.7 GHz to 2.24 GHz is implemented. In the field experimental results, it achieves the drain efficiency of above 62% at a fractional bandwidth of 22% with the gain of more than 10dB.