A 5GHz LC VCO with extended linear-range varactor in purely digital 0.15um CMOS Process

Author

Dec, Aleksander ; Akima, Hiroshi ; Suyama, Ken

Author_Institution

Epoch Microelectron., Inc., Tarrytown, NY, USA

fYear

2009

fDate

7-9 June 2009

Firstpage

567

Lastpage

570

Abstract

MOSFET varactors with two different threshold voltages are used for extending linear tuning range of a voltage controlled oscillator (VCO). This method is suitable for VCOs implemented in purely digital CMOS processes where MIM-capacitors are not available and only MOS transistors can be used for tuning element. The effectiveness of this technique is demonstrated in a 5 GHz LC VCO with divide-by-2, output buffer, and integrated low-dropout voltage regulator. The VCO consumes 4 mA of current and achieves a tuning range of 4.18-4.94 GHz as well as phase noise of -109 dBc/Hz at 1 MHz from 4.5 GHz carrier. The effective linear range has been extended by 38 percent.

Keywords

CMOS digital integrated circuits; MIM devices; MOSFET; varactors; voltage-controlled oscillators; LC VCO; MIM-capacitors; MOS transistors; MOSFET varactors; current 4 mA; divide-by-2; frequency 1 MHz; frequency 4.18 GHz to 4.94 GHz; frequency 5 GHz; integrated low-dropout voltage regulator; linear tuning range; output buffer; size 0.15 mum; tuning element; um CMOS Process; voltage controlled oscillator; CMOS process; Gain; MOSFETs; Phase noise; Regulators; Threshold voltage; Tuning; Varactors; Voltage control; Voltage-controlled oscillators; linear-range varactor; voltage controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Radio Frequency Integrated Circuits Symposium, 2009. RFIC 2009. IEEE

Conference_Location

Boston, MA

ISSN

1529-2517

Print_ISBN

978-1-4244-3377-3

Electronic_ISBN

1529-2517

Type

conf

DOI

10.1109/RFIC.2009.5135605

Filename

5135605