Design of compact-sized class-F PA for wireless handset applications

In this paper, a highly efficient and compact 840 MHz class-F amplifier using E-pHEMT FET is implemented with the minimal footprints, where only the 2^nd and 3^rd harmonics is controlled to obtain the high efficiency within the harmonic control circuit. Compared to the transmission line, the discrete LC network is a more suitable solution to the small-sized implementation when it is carefully designed for the maximum performance. As such, this paper shows that the small-sized class-F PA can equally perform the ones with transmission lines for the harmonic control, and is more suitable for compact sized wireless terminal applications. The implemented power amplifiers have the peak efficiency of 81.2% with output power of 24.4 dBm.