A new coupling scheme for multiphase and quadrature signals generation

A new coupling technique for low-phase noise low-power quadrature signals generation is presented. In the proposed technique two identical CMOS LC-voltage-controlled oscillators (VCOs) are coupled in an in-phase anti-phase manner via the substrates of the MOS varactors. Use of substrates (in other words the intrinsic gate-bulk capacitances) of the MOS varactors for coupling, results in elimination of any extra coupling elements and also their associated noises. Utilizing the proposed technique, a quadrature VCO (QVCO) is designed and simulated in TSMC 0.18 μm RF-CMOS technology. The phase noise of the proposed LC-QVCO is −137.5 dBc/Hz at 3 MHz frequency offset from 5.4 GHz center frequency, while the total DC current drawn from a 1.8-V power supply is 8.37 mA. Generalizing the proposed coupling scheme to several identical LC-VCOs, low-phase noise multiphase signals can be generated. The proposed circuits can operate with power supplies as low as 0.6 V without any performance degradation.

[1]  Sang-Gug Lee,et al.  A very low-power quadrature VCO with back-gate coupling , 2004, IEEE J. Solid State Circuits.

[2]  Sasan Naseh,et al.  A CMOS low-noise low-power quadrature LC oscillator , 2009, 2009 IEEE International Symposium on Circuits and Systems.

[3]  M. Tiebout,et al.  Low-power low-phase-noise differentially tuned quadrature VCO design in standard CMOS , 2001, IEEE J. Solid State Circuits.

[4]  Salvatore Levantino,et al.  A low-phase-noise 5-GHz CMOS quadrature VCO using superharmonic coupling , 2003, IEEE J. Solid State Circuits.

[5]  P. Kinget,et al.  A Low Phase Noise Quadrature LC VCO Using Capacitive Common-Source Coupling , 2006, 2006 Proceedings of the 32nd European Solid-State Circuits Conference.

[6]  A. Bonfanti,et al.  Analysis and design of a 1.8-GHz CMOS LC quadrature VCO , 2002, IEEE J. Solid State Circuits.

[7]  Mohammad Asyaei,et al.  A low-phase noise injection-locked quadrature voltage-controlled oscillator , 2012 .

[8]  J. Ackermann,et al.  Analysis and Design , 1993 .

[9]  Sheng-Lyang Jang,et al.  A 0.18 $\mu$ m CMOS Quadrature VCO Using the Quadruple Push-Push Technique , 2010, IEEE Microwave and Wireless Components Letters.

[10]  Yi-Jan Emery Chen,et al.  A low-voltage low-phase-noise bottom-series LC QVCO using capacitor tapping technique , 2008, 2008 IEEE MTT-S International Microwave Symposium Digest.

[11]  Sanjay Raman,et al.  Large-signal analysis of MOS varactors in CMOS -G/sub m/ LC VCOs , 2003 .

[12]  Asad A. Abidi,et al.  A single-chip 900-MHz spread-spectrum wireless transceiver in 1-/spl mu/m CMOS. I. Architecture and transmitter design , 1998 .

[13]  Behzad Razavi,et al.  RF Microelectronics , 1997 .

[14]  Beomsup Kim,et al.  A low-phase-noise CMOS LC oscillator with a ring structure , 2000 .

[15]  Y. Wang,et al.  A Low hase Noise Quadrature LC-VCO in 0.18-μm CMOS Technology , 2008, 2008 Global Symposium on Millimeter Waves.

[16]  Christian C. Enz,et al.  Realization of a low-voltage and low-power Colpitts quadrature oscillator , 2006, 2006 IEEE International Symposium on Circuits and Systems.

[17]  Sasan Naseh,et al.  A new robust capacitively coupled second harmonic quadrature LC oscillator , 2011 .