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 235GHz. We designed this circuit and fabricated the chip in Northrop Grumman Space Technology's (NGST) 0.07-μm InP high electron mobility transistor (HEMT) process. Using a WR3 (220-325GHz) 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 230GHz.