The Second Source Harmonic Optimization in Continuous Class-GF Power Amplifiers

• Published in: IEEE microwave and wireless components letters Vol. 32; no. 4; pp. 316 - 319
• Main Authors: Eskandari, Sina, Kouki, Ammar B.
• Format: Journal Article
• Language: English
• Published: IEEE 01.04.2022
• Subjects: Aerospace electronics; Class F; class GF; continuous-mode power amplifier (PA); gallium nitride (GaN); Harmonic analysis; high efficiency; Impedance; Logic gates; Tuning; tuning second source harmonic; Voltage; Wideband
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2021.3128497

In this letter, the second source harmonic in continuous-mode class GF (CCGF) is optimized to flatten the power amplifier's (PA) frequency response over a wideband. A new design space is explored by considering the effects of controlling the input nonlinearity of the gate-source capacitance (<inline-formula> <tex-math notation="LaTeX">C_{\mathrm {gs}} </tex-math></inline-formula>) on the drain current waveforms under continuous-mode drain voltage waveforms. A wideband CCGF PA is designed and fabricated using a commercial 10-W gallium nitride (GaN) device and low-temperature co-fired ceramic (LTCC) technology. Results of the measurement show a flat frequency response from 3.3 to 4.3 GHz with variations less than ±0.4 dB for 40 dBm output power, and 17 dB large signal gain at 3-dB compression point. A drain efficiency of 66 ± 2% is achieved over the entire bandwidth.