Analysis of RF scattering parameters and noise and power performances of RF‐power MOS in 0.15‐μm RF cmos technology for RF SOC applications

Abstract

AbstractIn this paper, we demonstrate an analysis of the effects of transconductance gm on the kink phenomenon of the scattering parameters S11, S22, S21, and S12 of RF power n‐MOSFETs in 0.15‐μm RF CMOS technology for RF SOC applications. It is found that either the increase of the device's width or the increase of the gate‐source voltage VGS (when its corresponding gm is smaller than the maximum gm) and the decrease of the measurement temperature can enhance the kink effect of both S11 and S22 due to the increase of gm. The anomalous dip in the S11 and S22 of RF power n‐MOSFETs can also be interpreted in terms of poles and zeros. In addition, we conclude that a device with larger gate width or larger gm exhibits better RF noise and power performances because of higher gain (or gm) and the lighter effect of the parasitic extrinsic elements. The present analyses enable RF engineers to understand more deeply the behaviors of S parameters, RF noise and power performances of RF power MOSFETs, and hence is helpful for them to create a fully scalable wideband RF‐power MOS or CMOS model for RF SOC applications. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 191–196, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20089