Design and experimental validation of class-F−1 GaN power amplifier using a compact harmonic control unit

In this paper, we present the design and implementation of an efficient inverse Class-F (Class-F−1) power amplifier (PA) using a compact Harmonic control unit (HCU). The HCU is implemented using a two-transmission line network that precisely controls the second and third harmonic impedances. The small size of the HCU reduces the circuit's overall layout and enables easy implementation. Tuning lines are utilized to better match the source and load impedances at the input and output. The design is substantiated by a PCB-fabricated prototype over a frequency range of 1 GHz to 2 GHz. For a bandwidth of 600 MHz (1200–1800 MHz), the proposed PA has a measured power-added efficiency (PAE) and output power of over 65% and 40 dBm, respectively.