Class-C VCO With Amplitude Feedback Loop for Robust Start-Up and Enhanced Oscillation Swing

Author

Wei Deng ; Okada, Kenichi ; Matsuzawa, Akira

Author_Institution

Dept. of Phys. Electron., Tokyo Inst. of Technol., Tokyo, Japan

Volume

48

Issue

2

fYear

2013

fDate

Feb. 2013

Firstpage

429

Lastpage

440

Abstract

We propose a feedback class-C voltage-controlled oscillator (VCO) that has robust start-up and a large oscillation amplitude. It initially starts oscillating as a conventional cross-coupled LC-VCO for robust start-up and subsequently transforms automatically into an amplitude-enhanced class-C VCO when it reaches steady-state to give improved noise performance. Detailed analysis of the start-up conditions, enhanced oscillation swing, and amplitude stability provides valuable insight into oscillator design considerations. The proposed VCO is implemented in a 0.18-μm CMOS process. The measured phase noise at room temperature is - 125 dBc/Hz at 1 MHz offset with a power dissipation of 3.4 mW at an oscillation frequency of 4.84 GHz. The figure-of-merit is -193 dBc/Hz.

Keywords

CMOS integrated circuits; MMIC oscillators; circuit feedback; circuit stability; field effect MMIC; phase noise; voltage-controlled oscillators; CMOS process; amplitude feedback loop; amplitude stability; amplitude-enhanced class-C VCO; cross-coupled LC-VCO; enhanced oscillation swing; feedback class-C voltage-controlled oscillator; frequency 4.84 GHz; large oscillation amplitude; oscillator design; phase noise; power 3.4 mW; power dissipation; robust start-up swing; size 0.18 mum; temperature 293 K to 298 K; Feedback loop; Logic gates; Phase noise; Robustness; Transistors; Voltage-controlled oscillators; CMOS; Class-C; PVT; VCO; feedback; start-up;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2012.2227603

Filename

6377236