A 6–18 GHz 13 W GaN Push–Pull Power Amplifier MMIC With Better Than −23 dBc Second Harmonic Suppression

Harmonics in broadband gallium nitride (GaN) power amplifiers (PAs) are usually quite strong, so additional filtering modules are required in practical applications, which degrade the system’s performance. Therefore, designing PAs with excellent harmonic suppression performance is of great significance. The push–pull architecture is a widely utilized technique for harmonic suppression. However, the design of a 6–18 GHz push–pull PA monolithic microwave integrated circuit (MMIC) poses significant challenges. This is attributed to the fact that on-chip broadband baluns typically exhibit high losses, which significantly degrade the PA’s performance. This article proposes a design method suitable for the 6–18 GHz high-performance push–pull PAs. Based on a 250-nm GaN HEMT technology, we design a three-line balun with a dissipation loss (DL) of less than 0.5 dB and utilize it in a 6–18 GHz 13 W push–pull PA MMIC. Under pulse-CW measurement conditions, the MMIC achieves a small gain of 19.7–23 dB, a saturated output power of 41.1–42.3 dBm, a saturated PAE of 18.8%–25.9% and a second harmonic suppression (HS2) of better than −23 dBc. To the best of the authors’ knowledge, this work is the first 6–18 GHz 10 W fully integrated GaN push–pull PA with good large-signal performance.