Title :
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
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;
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
DOI :
10.1109/VDAT.2006.258116
