Ultra-low-noise millimeter-wave pseudomorphic HEMTs

Pseudomorphic high-electron-mobility transistors (PHEMTs) with gate lengths of 0.1 mu m and based on the AlGaAs-InGaAs-GaAs material system are presented. The room-temperature device noise figure at 43 GHz is measured to be 1.32 dB (noise temperature=103 K) with 6.7 dB associated gain; when the device is cooled to 17 K, the noise figure falls to 0.36 dB (noise temperature=25 K) with 6.9 dB of associated gain. These pseudomorphic devices also show improved sensitivity to input noise match (N=0.13 at 43 GHz) compared with conventional HEMTs and MESFETs. These PHEMT devices have the lowest noise temperature and noise sensitivity (normalized to frequency) reported to date.<
>