A 2-W 37-40GHz GaAs Power Amplifier for 5G Applications

A 2-W 37-40GHz monolithic microwave integrated circuit (MMIC) power amplifier (PA) for 5G base station applications is presented in this paper. It adopts a balanced structure with two Lange couplers for input power division and output power combination. The unit cell is a class-AB power amplifier, which uses RC parallel networks for impedance matching and stability enhancement. The unit-cell PA also uses a dedicated output matching network with only 0.2dB power loss for linearity improvement. With the above-mentioned ideas, the presented PA was designed and fabricated based on a 0.13μm GaAs PHEMT technology, and shows advantages of measured high output power about 34dBm and power added efficiency of around 25% to 28% in the frequency range of 37-40GHz. The proposed PA has a measured flat gain around 25dB; the input and output reflection coefficient S11 and S22 is better than -14dB; and the output third-order intercept point is around 40dBm. In general, the proposed 5G PA exhibits an excellent overall measured performance including power gain, output power, PAE, and input/output matching.