Effect of device mismatch on the phase and amplitude accuracy in LC quadrature VCOs
- 28 April 2006
- proceedings article
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
An overview of cross-coupled LC tank quadrature VCOs is presented. Then, the effect of mismatch on the amplitude and quadrature phase accuracy is discussed. In particular, we focus on the mismatch between the negative resistance (Rneg) and quadrature resistance (R quad) of the two VCOs. By considering a first order linear model of the QVCO, it is shown that a mismatch in Rneg generates an imbalance in the quadrature phase but preserves the amplitude accuracy, whereas a mismatch in Rquad leads to both a relative amplitude error and phase imbalance. Furthermore, the mismatch leads to an effective coupling transconductance GMceff that in turn causes a deviation in the steady state oscillation frequency. The developed analysis is verified using SpectreRF simulation of a parallel QVCO topology (PQVCO)Keywords
This publication has 8 references indexed in Scilit:
- A low-phase-noise wide-band CMOS quadrature VCO for multi-standard RF front-endsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- A low-phase noise LC-QVCO in CMOS technologyIEEE Microwave and Wireless Components Letters, 2004
- Phase noise and accuracy in quadrature oscillatorsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2004
- A very low-power quadrature VCO with back-gate couplingIEEE Journal of Solid-State Circuits, 2004
- A 10-ghz cmos quadrature lc-vco for multirate optical applicationsIEEE Journal of Solid-State Circuits, 2003
- A 900 MHz CMOS LC-oscillator with quadrature outputsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Analysis and design of a 1.8-GHz CMOS LC quadrature VCOIEEE Journal of Solid-State Circuits, 2002
- CMOS mixers and polyphase filters for large image rejectionIEEE Journal of Solid-State Circuits, 2001