An Improved Low Phase Noise LC-VCO with Wide Frequency Tuning Range Used in CPPLL

Xiaofeng Wang, Zhiyu Wang, Haoming Li, Rongqian Tian, Jiarui Liu, Faxin Yu


Based on TSMC 0.18μm CMOS process, a complementary cross-coupled differential LC voltage controlled oscillator (LC-VCO) used in charge pump phase-locked loop (CPPLL) frequency synthesizer for satellite receiver with low phase noise and wide frequency tuning range is designed and implemented. The VCO adopts self-bias structure to remove flicker noise produced by tail current. Programmable LC tanks are introduced at the common source of cross-couple transistors to eliminate second harmonics of resonant frequency. Distributed biasing is applied for a wider linear tuning range. An optimized switch is proposed to lower on-resistance. The measured results show that the VCO exhibits a 53.8% tuning range from 1.02GHz to 1.77GHz. From the carrier frequency of 1.4 GHz, the phase noise of the VCO can reach -131.2 dBc/Hz at 1MHz offset. The core circuit consumes 7.7mA with 1.8V supply voltage.


low phase noise, wide tuning range, distributed biasing, optimized switch

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Q. Gu,RF system design of transceivers for wireless communications, Springer Science & Business Media, 1st ed.,2005.

B. Razavi,RF Microelectronics, Prentice Hall, 2nd ed., 2012.

A. Mehrotra, "Noise analysis of phase-locked loops," IEEE/ACM International Conference on Computer-aided design, Nov. 2000.

D.B. Leeson, "A simple model of feedback oscillator noise spectrum," Proceedings of the IEEE,vol.54, no.2 pp.329-330,1966.

B. Razavi, "A study of phase noise in CMOS oscillators," IEEE Journal of Solid-State Circuits, vol. 31, no. 3, pp. 331-343, Aug. 1996.

A. Hajimiri and T.H. Lee, "A general theory of phase noise in electrical oscillators." IEEE Journal of Solid-State Circuits, vol. 33, no.2, pp. 179-194, Feb.1998.

F. Pepe, A. Bonfanti, S. Levantino, C. Samori, and A.L. Lacaita,"Analysis and minimization of flicker noise up-conversion in voltage-biased oscillators," IEEE Trans. Microw. Theory Tech., vol. 61, no. 6, pp. 2382-2394, Jun. 2013

P. Andreani, K. Kozmin, P. Sandrup, M. Nilsson, and T. Mattsson, "A Tx VCO for WCDMA/EDGE in 90 nm RF CMOS,"IEEE J. Solid State Circuits, vol. 46, no. 7, pp. 1618-1626, Jul. 2011.

C.Sánchez-Azqueta, et al., "High-resolution wide-band LC-VCO for reliable operation in phase-locked loops," Microelectronics Reliability, vol. 63, pp. 251-255, 2016.

R. W. Rhea, Oscillator Design and Computer Simulation, New York: McGraw-Hill, 2nd ed., 1995.

Y.H. Kao and M.T. Hsu, "Theoretical analysis of low phase noise design of CMOS VCO," IEEE Microwave & Wireless Components Letters, vol.15, no.1, pp. 33-35, 2005.

E. Hegazi, H. Sjoland, and A.A. Abidi, "A filtering technique to lower LC oscillator phase noise," IEEE Journal of Solid-State Circuits, vol. 36, no. 12, pp. 1921-1930, 2001.

J. Mira, et al. "Distributed MOS varactor biasing for VCO gain equalization in 0.13 μm CMOS technology," IEEE Radio Frequency Integrated Circuits Symposium, pp. 131-134, 2004.

J. Kim, J.O. Plouchart, N. Zamdmer, et al., "A 44 GHz differentially tuned VCO with 4 GHz tuning range in 0.12 μm SOI CMOS," IEEE Int Solid-State Circuits Conf, Dig Tech Papers, pp. 1-416, 2005.


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