Integrated LC Voltage-controlled Oscillator Research Articles

A 2.4 GHZ Fully Integrated LC VCO Design Using 130 NM CMOS Technology

In this paper, a 2.4 GHz fully integrated LC voltage controlled oscillator (VCO) for RF wireless applications is presented. The VCO circuit is designed using TSMC 130 nm CMOS process. The circuit design is based on differential oscillator structure with cross-coupled NMOS transistors which achieves low power dissipation and low phase noise. Simulation and layout of the VCO is carried out using ADS Tool. The VCO operates from a supply voltage of 1.8 V and consumes 19.62 mW of power. After simulating the proposed design the VCO shows a phase noise of -128.68 dBc/Hz at 1 MHz offset frequency from a 2.4 GHz carrier signal. The frequency range of the VCO is from 2.36 GHz to 2.61 GHz when the control voltage changes from 0 to 2 V. The FOM is obtained as -183.73 dBc/Hz. The total chip area, including pads, occupies 0.7 mm × 0.7 mm.

Concepts and methods in optimization of integrated LC VCOs

Underlying physical mechanisms controlling the noise properties of oscillators are studied. This treatment shows the importance of inductance selection for oscillator noise optimization. A design strategy centered around an inductance selection scheme is executed using a practical graphical optimization method to optimize phase noise subject to design constraints such as power dissipation, tank amplitude, tuning range, startup condition, and diameters of spiral inductors. The optimization technique is demonstrated through a design example, leading to a 2.4-GHz fully integrated, LC voltage-controlled oscillator (VCO) implemented using 0.35-/spl mu/m MOS transistors. The measured phase-noise values are -121, -117, and -115 dBc/Hz at 600-kHz offset from 1.91, 2.03, and 2.60-GHz carriers, respectively. The VCO dissipates 4 mA from a 2.5-V supply voltage. The inversion mode MOSCAP tuning is used to achieve 26% of tuning range. Two figures of merit for performance comparison of various oscillators are introduced and used to compare this work to previously reported results.