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A technique to suppress tail current flicker noise in CMOS LC VCOs

Saeedi, S ; Sharif University of Technology | 2006

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  1. Type of Document: Article
  2. DOI: 10.1109/ISCAS.2006.1693313
  3. Publisher: 2006
  4. Abstract:
  5. A technique to reduce close-in phase noise in CMOS LC voltage controlled oscillators is proposed. In CMOS differential LC oscillators, the up-conversion of flicker noise mainly determines the close-in phase noise. The flicker noise of the bias current is a major component contributing to the overall low frequency noise. In this paper, a switched biasing technique to suppress the flicker noise of the bias circuit is presented. A 1.8v 2.4GHz differential LC VCO is designed in a 0.18u CMOS technology using this technique. With the proposed switching technique, the close in phase noise is improved as much as 15dB at 500 kHz offset. The simulated phase noise at the offsets of 500 kHz and 1 MHz is -124.6dBc/Hz and -130.3dBc/Hz, respectively. The VCO consumes 2mA from a 1.8v power supply. © 2006 IEEE
  6. Keywords:
  7. Close-in phase noise ; Frequency noise ; Switching technique ; Bias currents ; CMOS integrated circuits ; Computer simulation ; Natural frequencies ; Variable frequency oscillators ; Noise abatement
  8. Source: ISCAS 2006: 2006 IEEE International Symposium on Circuits and Systems, Kos, 21 May 2006 through 24 May 2006 ; 2006 , Pages 3229-3232 ; 02714310 (ISSN); 0780393902 (ISBN); 9780780393905 (ISBN)
  9. URL: https://ieeexplore.ieee.org/abstract/document/1693313