Beyond G-Band: A 235 GHz InP MMIC amplifier

We present results on an InP monolithic millimeter-wave integrated circuit (MMIC) amplifier having 10-dB gain at 235 GHz. We designed this circuit and fabricated the chip in Northrop Grumman Space Technology's (NGST) 0.07-mu m InP high electron mobility transistor (HEMT) process. Using a WR3 (220-325 GHz) waveguide vector network analyzer system interfaced to waveguide wafer probes, we measured this chip on-wafer for S-parameters. To our knowledge, this is the first time a WR3 waveguide on-wafer measurement system has been used to measure gain in a MMIC amplifier above 230 GHz. Index Terms-G-Band, high electron mobility transistors (HEMTs), indium phosphide, millimeter wave field-effect transistor (FET) amplifiers, monolithic millimeter-wave integrated circuits (MMICs), WR3 waveguide.