This paper presents the design and performance of 110-GHz low noise amplifier MMICs, based on coplanar technology, and utilizing 120-nm gate-length Metamorphic HEMTs. Thanks to a cascode device, a single-stage amplifier achieves 8-dB small signal gain, with less than 4-dB noise figure at 105 GHz, within a chip size of only 0.725 mm2. The 2- and 3-stage LNAs exhibit small signal gains of more than 15- and 22-dB, respectively over the 100-115 GHz frequency range, with associated measured noise figures of 4.5 dB at 105 GHz; the chip area for these circuits are less than 2- and 3 mm2. To the author’s knowledge, these results are amongst the lowest noise figures reported to date for uniplanar amplifier MMICs operating at these frequencies
