Title :
Analysis and Design of Dual-Mode CMOS LC-VCOs
Author :
Buonomo, Antonio ; Lo Schiavo, Alessandro
Author_Institution :
Dipt. di Ing. Ind. e dell´Inf., Seconda Univ. degli Studi di Napoli, Aversa, Italy
Abstract :
We present a nonlinear analysis of the basic circuit of a dual-band voltage controlled oscillator (VCO), composed by an active one-port and by a double-tuned LC circuit. Both the frequencies and the amplitudes of the two modes of sinusoidal oscillation are calculated by closed-form expressions by which a detailed analysis of the steady-state and dynamical behavior of circuit is performed, including the stability analysis of the modes. We show the appearance of the phenomenon of the frequency hysteresis allowing us to explain the mechanism of the switching between modes and predict the VCOs performance over the whole operation range. The theoretical results, validated by Spice simulations of a VCO realized in 0.13 μm MOS technology and by measurements on a circuit prototype, provide useful design insights.
Keywords :
CMOS analogue integrated circuits; LC circuits; voltage-controlled oscillators; Spice simulations; active one-port; circuit prototype; closed-form expressions; double-tuned LC circuit; dual-mode CMOS LC-VCO; dynamical behavior; frequency hysteresis; nonlinear analysis; sinusoidal oscillation; size 0.13 mum; stability analysis; steady-state behavior; voltage controlled oscillator; Circuit stability; Couplings; Harmonic analysis; Hysteresis; Stability analysis; Voltage-controlled oscillators; Analog integrated circuits; dual-band voltage-controlled oscillators (VCO); microwave oscillators; multiband VCOs; nonlinear systems;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2015.2426956
