A High-Efficiency Class-AB MMIC Power Amplifier Using GaAs HBT Technology

This paper presents the design and measurement results of a Class-AB two-stage power amplifier (PA) fabricated in a GaAs HBT process for Family Radio Service (FRS) applications. The chip has a compact size, measuring 0.99 x 1.09 mm2, and is enclosed in a 3 x 3 mm DFN-10 package, with the matching networks integrated on a two-layer FR4 board. The measurement results, obtained at a voltage of 3.4V and a frequency of 450MHz, showcase remarkable performance. The maximum power-added efficiency (PAE) is 66.3% and the saturated power is 29.5 dBm. Furthermore, the 1 dB compression point is achieved with a PAE of 53.9%, an output power of 27.3 dBm, 2<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> harmonic rejection of -24 dBc and IMD3 for two-tone signal with 1 kHz tone spacing of -19 dBc. The results demonstrate the power amplifier's high efficiency, output power capability, well control external matching network, and second harmonic impedance in optimizing its performance for wireless communication systems.