RF-Noise Modeling in Advanced CMOS Technologies

RF circuit design in deep-submicrometer CMOS technologies relies heavily on accurate modeling of thermal noise. Based on Nyquist's law, predictive modeling of thermal noise in MOSFETs was possible for a long time, provided that parasitic resistances and short-channel effects were properly accounted for. In sub-100-nm technologies, however, microscopic excess noise starts to play a significant role and its incorporation in thermal noise models is unavoidable. Here, we will review several crucial ingredients for accurate RF noise modeling, with emphasis on sub-100-nm technologies. In particular, a detailed derivation and discussion are presented of our microscopic excess noise model. It is shown to qualitatively explain the observed noise (across bias and geometry) in a wide range of commercially available sub-100-nm foundry processes. Besides, the impact of excess noise on the minimum noise figure is discussed.