Design of a High-Efficiency Extended Continuous-Mode Inverse Class-GF Power Amplifier With Enhanced Bandwidth

This letter provides an extended continuous-mode inverse class-GF (ECCGF<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>) concise theory for the design of a high-efficiency power amplifier (PA) with enhanced bandwidth. Compared with the typical continuous-mode inverse class-GF (CCGF<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>), a broader design space considering input nonlinearity is explored by simplified formulas based on the harmonic components of the drain current in class-GF<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>. Moreover, the problem of current overshoot can be alleviated in ECCGF<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>. For verification, a prototype is designed and fabricated by using a 10-W GaN HEMT device. The measured results show that the output power of 39.8–42.2 dBm, drain efficiency (DE) of 61%–78.6%, and gain of 9.8–12.2 dB are achieved over the relative bandwidth (RBW) of 136.8% from 0.6 to 3.2 GHz. In contrast with the other types of PA, the design exhibits a wider bandwidth and comparable efficiency.