A 750-W AlGaN/GaN HEMT Operating at 80 V for <inline-formula> <tex-math notation="LaTeX">$L$ </tex-math> </inline-formula>-Band Applications

High operating voltage and high power are important developing goals of GaN-based high-electron mobility transistor (HEMT) at present. In this letter, we demonstrated a GaN-based HEMT exhibiting a breakdown voltage of greater than 300 V, an operating voltage of up to 80 V, an output power of up to 750 W, a power-added efficiency (PAE) of 80% and an associated power gain of 16.8 dB at 1.3 GHz. The device simultaneously realizes high voltage, high power, and high PAE, and is suitable for ${L}$ -band high-power applications.