A study of capacitor-coupled varactor VCO to investigate flicker noise up-conversion mechanism

Author

Itoh, Nobuyuki

Author_Institution

Dept. of Analog RF Syst. Eng., Toshiba Corp., Yokohama, Japan

fYear

2005

fDate

30 Nov.-2 Dec. 2005

Firstpage

157

Lastpage

160

Abstract

CCV-VCO (capacitor-coupled varactor VCO) has been studied with a view to suppressing flicker noise up-conversion. The mechanisms of flicker noise up-conversion to f³ phase noise utilize three paths; direct modulation, folding by non-linearity of oscillation, and tail current up-conversion at common node. Designed NMOS-VCO satisfied to avoid f³ phase noise by direct modulation pass. Measured phase noise at 10 kHz offset from carrier was -74 dBc/Hz at 2.9 GHz oscillation frequency, and the corner frequency between f³ phase noise and f² phase noise was approximately 20 kHz. The current consumption was 6 mA with 1.8 V. The 1 MHz FOM of VCO was 182 dB and 10 kHz FOM of VCO was 173 dB.

Keywords

circuit noise; coupled circuits; flicker noise; interference suppression; phase noise; varactors; voltage-controlled oscillators; 1.8 V; 10 kHz; 173 dB; 182 dB; 2.9 GHz; 6 mA; capacitor-coupled varactor VCO; current consumption; direct modulation pass; flicker noise up-conversion suppression; oscillation frequency; oscillation nonlinearity; phase noise; 1f noise; Bandwidth; Frequency; MOSFET circuits; Mobile communication; Phase modulation; Phase noise; Tail; Varactors; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Radio-Frequency Integration Technology: Integrated Circuits for Wideband Communication and Wireless Sensor Networks, 2005. Proceedings. 2005 IEEE International Workshop on

Print_ISBN

0-7803-9372-4

Type

conf

DOI

10.1109/RFIT.2005.1598899

Filename

1598899