A 17–26.5 GHz 42.5 dBm broadband and highly efficient gallium nitride power amplifier design

A gallium nitride (GaN) power amplifier mono‐ lithic microwave integrated circuit (MMIC) with a wide band and high efficiency in the microwave fre‐ quency band is proposed in this study. The power am‐ plifier MMIC uses a 0.15 μm GaN high electron mo‐ bility transistor (HEMT) process. The operating fre‐ quency band of the amplifier can cover the whole K-band, i.e., 17–26.5 GHz. To obtain better output power and power added efficiency (PAE), the power amplifi‐ er MMIC is designed with the optimal driving ratio of the front and rear stages and the optimal size of the transistor according to the performance of the transis‐ tor, and a broadband low-loss circuit topology is adopt‐ ed to realize the broadband high-efficiency design. The harmonic control structure is integrated into the drive-stage matching circuit to improve the high-frequency efficiency and keep the PAE high performance in the whole frequency band. In the continuous wave (CW) mode, results show that the power amplifier, using a three-stage topology, demonstrates over 42.5 dBm sat‐ urated output power in the frequency range of 17 – 26.5 GHz, an average PAE of 30%, and the maximum value of PAE is 32.1% at 19.8 GHz. The output power flatness is better than 1.0 dB. The chip has a compact structure and an area of 4.2 mm×3.0 mm, and can be widely used in transceiver components, wireless com‐ munications, electronic measuring instruments, etc.