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An analysis of the kink phenomenon of scattering parameter S 22 in RF power mosfets for system‐on‐chip (SOC) applications
Author(s) -
Lin YoSheng,
Lu SheyShi
Publication year - 2003
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.10767
Subject(s) - smith chart , microwave , offset (computer science) , scattering , electrical engineering , electrical impedance , scattering parameters , power mosfet , power (physics) , engineering , radio frequency , rf power amplifier , optoelectronics , physics , mosfet , materials science , voltage , impedance matching , cmos , transistor , optics , telecommunications , computer science , programming language , quantum mechanics , amplifier
In this paper, the kink effect in scattering parameter S 22 of RF power MOSFETs with drain‐to‐spacer offset is explained quantitatively for the first time. Our results show that for RF power MOSFETs the output impedance can be represented by a “shifted” series RC circuit at low frequencies and a “shifted” parallel RC circuit at high frequencies. The appearance of the kink point of S 22 in a Smith chart is caused by this inherent ambivalent characteristic of the output impedance. It is found that an increase of drain‐to‐spacer offset enhances the kink effect. In addition, the kink effect in S 22 of RF power MOSFETs can also be interpreted in terms of poles and zeros. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 371–376, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10767