Prof. Chun-Huat Heng (S’96-M’04) received the B. Eng. and M. Eng. degrees from the National University of Singapore in 1996 and 1999, respectively, and the Ph. D. degree from the University of Illinois at Urbana-Champaign in 2003. From 2001 to 2004, he was with Wireless Interface Technologies, which was later acquired by Chrontel. Since 2004, he has been with the National University of Singapore. He has been working on CMOS integrated circuits involving the synthesizer, DLL and transceiver.
Abstract:
In this paper, we review some of the well known techniques for improving the performance of CMOS tail current biased LC VCO, such as the phase noise and the tuning range. Based on the better understanding on VCO phase noise mechanism and tuning range limitations, this has lead to newly developed techniques such as noise cancellation VCO and resistively tuned variable inductor, which help improving the VCO performance. The former technique achieves FOM of -186dBc/Hz while the latter leads to wide tuning range VCO of 56% suitable for tuner application.