Title :
An Analysis of 1/f2 Phase Noise in Bipolar Colpitts Oscillators (With a Digression on Bipolar Differential-Pair LC Oscillators)
Author :
Fard, Ali ; Andreani, Pietro
Author_Institution :
Dept. of Comput. Sci. & Electron., Malardalen Univ., Vasteras
Abstract :
This work presents an analysis of phase noise in the 1/f2 region displayed by both single-ended and differential bipolar Colpitts oscillators. Very accurate and rigorous symbolic phase noise expressions are derived, enabling a deeper insight into the major mechanisms of phase noise generation, and providing new tools for design optimization. Phase noise expressions for the cross-coupled differential-pair LC-tank oscillator are derived as well. The theoretical analysis is validated on a 3 GHz differential bipolar Colpitts VCO implemented in a 0.35 mum SiGe process. Measurements show a phase noise of -123 dBc/Hz or less at 1MHz offset frequency from the 2.8-3.1 GHz carrier, for a phase noise figure-of-merit of at least 183 dBc/Hz across the tuning range. A very good agreement between theory, numerical simulations, and measurements is observed
Keywords :
1/f noise; bipolar integrated circuits; integrated circuit noise; phase noise; voltage-controlled oscillators; 0.35 micron; 1/f phase noise; 2.8 to 3.1 GHz; SiGe; bipolar Colpitts oscillators; bipolar differential-pair LC oscillators; differential-pair LC-tank oscillator; symbolic phase noise expressions; voltage controlled oscillator; Design optimization; Frequency measurement; Germanium silicon alloys; Noise measurement; Numerical simulation; Phase measurement; Phase noise; Silicon germanium; Tuning; Voltage-controlled oscillators; Bipolar; Colpitts; VCOs; oscillators; phase noise;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2006.889388
