On the Design of Highly Efficient Harmonic Tuned Wideband Class F-1/F Power Amplifier

Abstract

A novel methodology to design a highly efficient wideband Class F-1/F power amplifier using GaN HEMT is presented in this paper. The P A operates in Class F−1in lower half band and Class $F$ in higher half band, achieving the overall bandwidth in the frequency range of 1.4- 3.4 GHz. A matching network using a 6th and 8th-order low-pass chebyshev filters is designed at the output and input, respectively, which provide the optimal fundamental impedance and allow harmonic control up to the third order within an octave bandwidth. The main contribution of this work is the combination of two class (F−1/F) and design of wideband matching network for each band, also, the simple design of filters and the condition introduced for both frequency bands of operation to make the design simpler. With the proposed condition on the center frequency of each band, it is simpler to design matching networks to provide proper impedances for harmonics. Both simulation and measurement results show that an optimal Class F−1 PAis realized from 1.7 to 2.3 GHz with a measured efficiency of 66-83.8% and output power of 37–40 dBm. Meanwhile, the PA acts as an optimal Class $F$ amplifier in the frequency range of 3.2-3.4 GHz with a measured efficiency of 62-76% and output power of 38.7-40 dBm. The implemented P A achieves a measured bandwidth from 1.4-3.4 GHz with >36 dBm output power and >58% drain efficiency. The measurement results show that this PAis among the best reported works.