A 1–25 GHz GaN HEMT MMIC Low-Noise Amplifier

This letter presents an ultra-wideband low noise amplifier (LNA) using gallium-nitride (GaN) high-electron mobility transistors (HEMT) technology. A -3 dB bandwidth of 1-25 GHz with 13 dB peak power gain is achieved using a modified resistive-feedback topology. To obtain such a wide bandwidth, several bandwidth enhancement techniques are utilized. An inductor connected to the source of the input transistor ensures good input matching (|S 11 | <; -9 dB) across the entire bandwidth. The shunt feedback loop and the inductive source degeneration minimize all the required inductor values. This GaN HEMT LNA is believed to have the widest bandwidth among all GaN HEMT monolithic microwave integrated circuit (MMIC) LNAs reported to date. With 3.3 dB minimum noise figure (F), 33.5 dBm maximum output-referred third-order intercept point (OIP3), 20 dBm maximum output-referred 1 dB compression point (Output P1 dB), this MMIC amplifier is comparable in performance to distributed amplifiers (DAs) but with significantly lower power consumption and smaller area.