We developed a 300-GHz high gain amplifier MMIC in 75-nm InP high electron mobility transistor technology. We approached the issues with accurate characterization of devices to design the amplifier. The on-wafer through-reflect-line calibration technique was used to obtain accurate transistor characteristics. To increase measurement accuracy, a highly isolated structure was used for on-wafer calibration standards. The common source amplifier topology was used for achieving high gain amplification. The implemented amplifier MMIC exhibited a gain of over 25 dB in the 280-310-GHz frequency band.

A wide-bandwidth fundamental mixer operating at a frequency above 110GHz for precise spectrum analysis was developed using the InP HEMT technology. A single-ended resistive mixer was adopted for the mixer circuit. An IF amplifier and LO buffer amplifier were also developed and integrated into the mixer chip. As for packaging into a metal block module, a flip-chip bonding technique was introduced. Compared to face-up mounting with wire connections, flip-chip bonding exhibited good frequency flatness in signal loss. The mixer module with a built-in IF amplifier achieved a conversion gain of 5dB at an RF frequency of 135GHz and a 3-dB bandwidth of 35GHz. The mixer module with an LO buffer amplifier operated well even at an LO power of -20dBm.