On the class-F power amplifier design

Advances in Microwave Large-Signal Metrology: From Vector-Receiver Load-Pull to Vector Signal Network Analyzer and Time-Domain Load-Pull Implementations (Invited Paper)

“…Figure 22 shows the load lines along with the current and voltage waveforms of a GaN-HEMT measured when loading the transistor with the impedances for maximum output power. Note that the half-rectified shape of the drain-source current waveform and the rectangular shape of the drain-source voltage waveform are consistent with the theory [38]. Figure 23 shows the same set of load lines along with the current and voltage waveforms of a SiC-MESFET.…”

“…An example, Class-F, is presented. According to theory, the Class-F [37] operation mode should be biased as Class-AB mode but loading the intrinsic current generator with a short circuit and an open circuit at the second and third harmonic, respectively [38]. In Figure 21, the impedance design space of the Class-F modes for the fundamental, second, and third harmonics for a GaN-HEMT and SiC-MESFET are presented.…”

Implementation of Electromagnetic Theory: Improved Analysis and Design for Class F Power Amplifier

“…Here, voltage gain δ 1,Γ@F of CF PA is obtained with an increase in fundamental impedance (R 1,L@F ) where the input gate signal is fixed at v gs . That is exactly the same as the existing theory for CF PA [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Due to fixed input gate signal v gs , V s,1@F + is equal to V s,1@B + and ΔV s,1 + = 0.…”

Evaluation of GaN technology in Doherty power amplifier architectures

“…18 shows the comparison between the measured performances of the TL-DPA and the class F-DPA as a function of the output power. As can be noted, the class F-DPA shows a drain efficiency roughly 15% higher than the efficiency of the TL-DPA, as expected with a class F approach [17].…”