CMOS technology for RF application

CMOS has been used for advanced LSIs so many years because of its excellent low-power and high-speed characteristics for highly-integrated digital circuits. For high frequency analog applications such as RF, it has not been used popularly because CMOS has been assumed to have poor capability compared with silicon bipolar and compound semiconductor devices. However, recent miniaturization of CMOS devices has significantly improved the CMOS RF characteristics. For example, typical values of f_T and f_max for 0.25 μm n-MOSFETs already exceed 40 GHz, and those for 0.1 μm n-MOSFETs are more than 100 GHz. RF noise of the MOSFETs are also as good as less than 1 dB at 2 GHz operation. In this paper, CMOS technology for RF frontend circuit for mobile telecommunication devices is explained