A 280–310 GHz InAlAs/InGaAs mHEMT Power Amplifier MMIC with 6.7–8.3 dBm Output Power

This letter presents a broadband power amplifier (PA) millimeter-wave integrated circuit (MMIC) demonstrating 6.7-8.3-dBm measured output power from 280 to 310 GHz at -5-dBm input power. The measured small-signal gain is 15-20 dB for 266-330 GHz, which is the maximum frequency that could be measured. A dc power of 521 mW is required for this four-stage amplifier circuit using four cascode amplifier cells in parallel. The cascode PA cell is implemented with thin-film microstrip lines on the wafer front side using two two-finger devices with 10-μm finger width in parallel. Due to the compact cascode cell topology, the total gate width of 160 μm is realized requiring only 400 μm × 800 μm chipsize for the four-stage amplifier without pads. The reported output power represents the state of the art for mHEMT-based PA MMICs between 280 and 310 GHz.