An X-band low noise amplifier (LNA) using the 70 nm GaAs metamorphic high electron mobility transistors (mHEMT) process available from OMMIC has been reported. The foundry model-based simulated response, on-wafer measurements of the fabricated monolithic microwave integrated circuit (MMIC) LNA and measured data of packaged LNA at room temperature and 100 K have been shown. At room temperature, the packaged LNA exhibits a flat gain more than 26 dB from 7 to 11 GHz with less than 1 dB noise figure at room temperature. The input and output return losses are better than -20 and -10 dB, respectively, between 7.5 and 8.5 GHz. It exhibits linear response with output 1 dB compression point of 1 dBm. MMIC dimension has been limited to 1.5 mm × 1 mm. Off-chip inductance in the form of a modelled bondwire has been used to attain the improved input return loss and noise matching. Two figure-of-merits have been proposed and justified, and a comparative study of the overall performances of X-band LNAs with emerging technologies has been made. At 100 K, the LNA shows major improvement of the input and output return losses.