Comparison of nMOSFET Structures for Millimeter-Wave Frequencies in 0.18-μm CMOS technology

We present two nMOSFET structures with the high maximum oscillation frequency (f
max
) in 1P5M 0.18-$\mu$m CMOS technology to use it for millimeter-wave applications. One is a compact-type structure, and another is a round-table-type structure. By reducing their parasitics, we achieve the f
max
of 95 GHz, which is approximately 2 times or more compared to that of the conventional structure. It is shown that the f
max
of the round-table-type structure is approximately 10 GHz higher than that of the compact-type structure.