Noise Analysis of Common Source CMOS Pair for Dual-Band LNA

이중밴드 저잡음 증폭기 설계를 위한 공통 소스 접지형 CMOS쌍의 잡음해석

  • Cho, Min-Soo (Department of Information & Communication Engineering, Sungkyunkwan University) ;
  • Kim, Tae-Sung (Department of Information & Communication Engineering, Sungkyunkwan University) ;
  • Kim, Byung-Sung (Department of Information & Communication Engineering, Sungkyunkwan University)
  • 조민수 (성균관대학교 정보통신공학부) ;
  • 김태성 (성균관대학교 정보통신공학부) ;
  • 김병성 (성균관대학교 정보통신공학부)
  • Published : 2003.11.15

Abstract

This paper analyzes the output noise and the noise figure of common source MOSFET pair each input of which is separately driven in the different frequencies. This analysis is performed for concurrent dual band cascode CMOS LNA with double inputs and single output fabricated in $0.18{\mu}m$ CMOS process. Since both inputs and output are matched to near $50{\Omega}$ using on-chip inductors, the measured noise figures are much higher than those of usual CMOS LNA. But, the main concern of this paper is focused on the added noise features due to the other channel common source stage. The dual-band LNA results in noise figure of 4.54dB at 2.14GHz and 6.03dB at 5.25GHz for selectable operation and 7.44dB and 6.58dB for concurrent operation. The noise analysis explains why the added noise at each band shows so large difference.

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