Although there has been a large amount of research focusing on the noise performance of GaN HEMTs in L-bands and Ku-bands, few studies have focused specifically on the noise performance at mm-Wave frequencies. In this letter, the fabricated 120 nm MISHEMTs exhibited a low minimum noise figure (NFmin) of 1.3 dB with an associated gain (Ga) of 7.7 dB at 30 GHz, and NFmin of 1.7 dB and Ga of 6 dB at 40 GHz, showing the lowest values of NFmin compared with the reported GaN HEMTs with the same gate length.Â