VCO Type I • To maximize tuning range, we wish to minimize C1. • But C1 is given by: - Caps of M1 and M2 (including 4Cgd)-Cap of L1 - Input cap of next stage • Tuning range may be limited.

Table 1.1: List of ideal VCO specifications. As discussed below, it is unlikely that either the ringVCO (ring oscillator VCO) or LCVCO (LC tank VCO) topologies can meet all of these specifications. Through a comparison of ringVCOs and LCVCOs, the following advantages and disadvantages may be formulated. wide tuning range.

Using a library for CMOS 0.5um technology in cadence, create the schematic shown in figure 1. This is an LC-based CMOS voltage controlled oscillator (VCO) which is designed to operate around 1.9GHz. The component values are shown in tables 1-2.

VCO stands for Voltage Controlled Oscillator. VCO is an Oscillator of which frequency can be Controlled by external Voltage stimulus. One of major applications for VCO is a frequency synthesizer. Frequency synthesizer provides sinusoidal/pulse signals at predetermined frequencies that is precisely controllable by digital words.

A 3.5GHz LC-Tank VCO Phase Noise Measured Phase Noise-30dB/decade-20dB/decade-105dBc

LC Voltage-Controlled Oscillators CMOS Complementary Cross-coupled –G m LC VCO Design issues • Low phase noise • Low power • Wideband tuning range • F-V tuning curve • Quadrature output • etc...

a cross coupled LC-VCO with two main blocks is represented; the LC thank responsible for the oscillation frequency, and the active circuit which accounts for reducing the circuit losses by introducing a negative resistance. Most LC-VCO designs aim at achieving both minimum phase noise and power consumption for a certain oscillation frequency.

VCOs are the critical component of RF transceivers and are used to perform signal processing tasks such as frequency selection and signal generation. In digital circuits, oscillators are used to synchronize the operations using a reference clock.

CMOS LC voltage controlled oscillator (VCO) has been fully integrated in a commercial 0.18 µm CMOS process. To achieve low power and low phase noise, a complementary NMOS and PMOS cross-coupled differential LC structure is used. The LC tank is composed of octagonal-shaped inductors with 2 µm Al metal and standard NMOS varactors.

Analysis of two common LC VCO topologies. Design procedure for the cross-coupled LC VCO. Phase noise reduction techniques. Low phase noise. Wide tuning range. Low cost (i.e. compatible with IC process). Small size. Low power consumption. Only LC and transmission line VCOs are suitable for IC process.