High-Gain and High-Linearity MMIC GaN Doherty Power Amplifier With 3-GHz Bandwidth for Ka-Band Satellite Communications

This letter presents the design of a Doherty power amplifier (DPA) for satellite applications in the <tex-math notation="LaTeX">$Ka$</tex-math> -band downlink (17.3–20.3 GHz) implemented on a 100-nm GaN–Si HEMT technology. The design aims to achieve high gain and very high intrinsic linearity over a wide bandwidth of 3 GHz. The experimental characterization on the fabricated chip demonstrates that the DPA can maintain a noise-to-power ratio (NPR) higher than 25 dB and power-added efficiency (PAE) of 30% while providing 36 dBm of output power, when tested with a 100-MHz uniformly distributed signal, achieving state-of-the-art performance among the integrated power amplifiers for satellite communications.