100 W High Power Amplifier MMIC in 0.45 μm GaN Technology

Very high output power level is achieved at microwave frequencies using Gallium Nitride technologies due to high breakdown voltage, high current density and high carrier mobility in AlGaN/GaN based High Electron Mobility Transistors. The specific 0.45 $\mu$m AlGaN/GaN on SiC HEMT based MMIC technology is developed for this purpose to operate at high DC bias voltage of 50 V to achieve high power at microwave frequencies. This paper demonstrates that a high microwave power exceeding 100 W can be achieved from a single MMIC chip fully matched to 50 Ohm at S-band frequencies. In addition to high power, high power added efficiency greater than 50% is also achieved in this chip. The implemented high-power amplifier chip is a two-stage amplifier achieving output power greater than 50 dBm with power gain better than 22 dB, and power added efficiency exceeding 50% over frequency range of 3.1-3.5 GHz. The MMIC chip layout area is as compact as 5.8 $\times$ 3.3 mm2. The saturated output power density of transistor in this chip reaches value of 7 W/mm, maximum possible in this technology.