The Design Of QVCO For GPS/BD-2 Receiver

In recent years, with the rapid development of Portable Navigation Devices(PND) and smart-phones with navigation functions, all Commonwealth states, including our country, are beginning to deploy or have deployed their own global satellite positioning system. Satellite navigation signal receiver chip has become the industry's research focus.Quadrature voltage controlled oscillator(QVCO) is one of the most important part of RF receiver, this thesis studied the QVCO which is used in GPS/DB2 receiver based on the background of this application.This paper started from the theory of frequency synthesizer, analyzed each module in Phase Locked Loop and gave each module a simple circuit model and circuit realization; Started from ordinary oscillator'principle, analyzed the theory of general LC-VCO and QVCO which is composed of two coupled LC-VCO, derived the cause of multi-mode oscillation and frequency offset, phase shifter is proposed to give a solution of multi-mode oscillation; analyzed the mechanism of phase noise from two different models and gave some advices for low phase noise circuit design.The designed QVCO used in GPS/BD2 reciver is implemented by TSMC 0.18μm CMOS aluminum process. It covers frequency range of 1.3GHz-2GHz and consumes 4.5mA current at 1.8V power supply. Its phase noise performance is better than -71.2dBc/Hz at 10KHz, -98.1dBc/Hz at 100KHz and -119.8dBc/Hz at 1MHz respectively when operates at typical corner and room temperature.