A 50-nm gate-length metamorphic HEMT distributed power amplifier MMIC based on stacked-HEMT unit cells

This paper reports on a distributed power amplifier (DPA) millimeter-wave integrated circuit (MMIC) with high output power, high gain, and low noise figure. The ultra-wide bandwidth MMIC is based on the Fraunhofer IAF 50-nm gatelength metamorphic high-electron-mobility transistor (mHEMT) technology. The DPA uses eight stacked-HEMT unit power cells and covers a frequency range of more than 0-110 GHz. Due to the stacking approach of the unit cells it is possible to reach high output power and high gain over the designed frequency range with a single DPA stage. The average small-signal gain is 19:7 dB over the entire frequency range from 0 to 119 GHz. The noise figure yields a value between 2:5-6:4 dB for frequencies from 0 to 98 GHz. The saturated output power achieves an average value of 17:5dBm up to a frequency of 110 GHz, with a peak output power of 20 dBm.