An InAs-channel high-electron-mobility transistor (HEMT) with an 80nm gate length for ultralow-power low-noise amplifier (LNA) applications has been fabricated and characterized on a 2-in. InP substrate. Small-signal S-parameter measurements performed on the InAs-channel HEMT at a low drain-source voltage of 0.2V exhibited an excellent fT of 120GHz and an fmax of 157 GHz. At an extremely low level of dc power consumption of 1.2mW, the device demonstrated an associated gain of 9.7 dB with a noise figure of less than 0.8 dB at 12 GHz. Such a device also demonstrated a higher associated gain and a lower noise figure than other InGaAs-channel HEMTs at extremely low dc power consumption. These results indicate the outstanding potential of InAs-channel HEMT technology for ultralow-power spacebased radar, mobile millimeter-wave communications and handheld imager applications.