Design and implementation of High Performance Voltage-Controlled Oscillator using CMOS Technology

Abstract

In recent years, oscillators are considered as inevitable blocks in many electronic systems. They are commonly used in digital circuits to provide clocking and in analog/RF circuits of communication transceivers to support frequency conversion. Nowadays, CMOS technology is the most applicable solution for VLSI and especially for modern integrated circuits used in wireless communications. Additionally, the trend towards single chip implementation makes the circuit design increasingly challenging. The main purpose of this paper is to design a high performance voltage controlled oscillator ( VCO) using 90nm CMOS technology. In the beginning, a brief study of different VCO architectures is carried out. Next, a wide comparison between different VCO topologies is performed in terms of phase noise and power consumption. The effect of VCO phase noise on RF transceivers is also analyzed. In the following, all the phase noise contributors in a typical VCO are identified to enable design optimization. To meet the state‐of‐the‐art requirements, several circuit solutions have been explored and the design work ended‐up with a Quadrature VCO. The design is verified for the intended tuning range and process, temperature, and supply voltage (PTV) variations. The circuit operates at center frequency of 2.4 GHz. The phase noise of QVCO obtained by simulation is ‐140 dBc/Hz at 1MHz offset frequency which is 6 dB less compared to conventional VCOs. The power consumption is 3.6mW and the tuning voltage can be swept from 0.2 V to 1.2 V resulting in 2.25 GHz ‐ GHz frequency range..