A New CMOS VCO Topology with Capacitive Degeneration and Transformer Feedback

Author

Chuang, Yun-Hsueh ; Lee, Shao-Hua ; Lee, Chien-Feng ; Jang, Sheng-Lyang ; Juang, Min-Homg

Author_Institution

Dept. of Electron. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei

fYear

2006

fDate

26-28 April 2006

Firstpage

1

Lastpage

4

Abstract

This paper presents a new voltage controlled oscillator (VCO) topology for radio frequency operation. The low phase noise differential CMOS VCO uses capacitive degeneration and transformer coupling between the gate and source of the negative conductance transistor. An on chip transformer in positive feedback is used to increase the voltage swing in resonator and to improve the phase noise. The VCO is tunable from 2.85 GHz to 3.35 GHz with 16% tuning range, and has been fabricated with 0.18mum CMOS technology. The measured phase noise at 1 MHz offset is -119 dBc/Hz at the operation frequency of 3 GHz. The circuit draws 10 mA from a 1.8V supply

Keywords

CMOS integrated circuits; UHF oscillators; circuit feedback; integrated circuit noise; phase noise; resonators; transformers; voltage-controlled oscillators; 0.18 micron; 1.8 V; 10 mA; 2.85 to 3.35 GHz; CMOS voltage controlled oscillator; capacitive degeneration; differential CMOS; negative conductance transistor; on chip transformer; phase noise; positive feedback; radio frequency operation; resonator; transformer coupling; transformer feedback; voltage swing; CMOS technology; Circuit optimization; Feedback; Frequency measurement; Phase noise; Radio frequency; Topology; Tunable circuits and devices; Tuning; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Design, Automation and Test, 2006 International Symposium on

Conference_Location

Hsinchu

Print_ISBN

1-4244-0179-8

Electronic_ISBN

1-4244-0180-1

Type

conf

DOI

10.1109/VDAT.2006.258116

Filename

4027488