Design of 26-40 GHz 17 W GaN-based Balanced Power Amplifier MMIC

A wideband 26-40 GHz 17 W GaN power amplifier (PA) utilizing 0.15 mu m gallium nitride (GaN) high electron mobility transistor (HEMT) technology is presented in this letter. The MMIC is designed with balanced architecture to achieve low input/output return loss and reduce the load-pull effect on the performance degradation. A novel design method of optimizing load impedance of the Lange Coupler is presented, which solved the conflict between microwave performance and process design rules. The MMIC is designed with the load-pull method, with the final stage matched to compromise between output power and power added efficiency (PAE). An output power of more than 42 dBm and a power added efficiency of more than 15 % over the band of 26-40 GHz under a drain voltage of 20 V at CW mode have been achieved. The chip size is 3.5 mmx5.3 mm (18.55 mm(2)).