The design, monolithic microwave integrated circuit (MMIC) implementation, and testing of a 180 GHz doubler based on InP-HEMT (high electron mobility transistor) technology is reported. Doublers were fabricated using submicron (0.1 μm) InAlAs/InGaAs HEMTs. A simplified harmonic content study was employed in order to understand the power characteristics in HEMT doublers. The experimental conversion loss followed the predicted performance and showed a minimum conversion loss of 6 dB at 0 dBm input power. This is the first report of the monolithic HEMT doubler at 180 GHz.
