Design of high‐efficiency and broadband‐tuned class AB power amplifier

The design of broadband matching networks (MNs) exploiting filter theory is presented in this article for synthesizing broadband and highly efficient power amplifiers (PAs). Starting from sets of optimum impedances over the design frequency (obtained from load/pull measurement), the MNs are designed using a systematic approach. The impact of the second harmonic termination art the transistor performance is investigated and used to optimize the power efficiency over broad frequency range. Two PAs were designed with the proposed methodology using 25-W GaN device. The designs targeted the frequency bands of 1.8-2.2 GHz (20% BW) and 1.8-2.7 GHz (40% BW). The former achieved the drain efficiency (DE) of about 70% and output power of 45.5 dBm (+/- 1 dB), whereas the latter delivered a DE of about 60% and output power of 45.5 dBm. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:395-398, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25710