A 10-W 7-GHz GaN-on-Si Doherty Power Amplifier with Hybrid MMIC-Module Integration for 6G FR3 Base-Station Applications

This paper presents a 7-GHz GaN-on-Si HEMT Doherty power amplifier (DPA), which integrates phase-critical networks on-chip. The proposed hybrid MMIC-module architecture ensures precise Doherty operation with enhanced bandwidth while retaining matching flexibility off-chip, enabling robust operation in the FR3 band. The MMIC occupies a core area of 1.17 × 2.25 mm². The DPA evaluation board (EVB) achieves a peak gain of 8.2 dB and a saturated power (Psat) of 40.3 dBm at 7.4 GHz. For the 64-QAM 100-MHz OFDM signals, the DPA provides an average output power (Pavg) of 33–33.3 dBm, resulting in a drain efficiency (DE) ranges from 43.1 to 44.3% at Pavg across carrier frequencies from 7 to 7.8 GHz, while an adjacent channel leakage ratio (ACLR) satisfies below -29.4 dBc at 7.4 GHz. To the best of the authors' knowledge, this study presents the first implementation of a partially integrated GaN-on-Si MMIC DPA operating at 7 GHz.