The Design and Analysis for 5GHz Voltage-Controlled Oscillator

• Main Author: 蔡文彬
• Other Authors: 龔正
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/29324164698805114980

碩士 === 國立清華大學 === 電子工程研究所 === 90 === In this thesis, 0.18μm CMOS technology is used to design oscillators working at 5GHz for wireless applications. The simulation tool used is the ADS 1.5. At first, we introduce the fundamental components of oscillator, and discuss their behaviors in RF band. The architectures of oscillator are cross-coupled pair and complementary cross-coupled pair. The output signal is in differential form. Phase noise is an important factor of oscillator in RF transceiver systems. Therefore, Lesson model and time-variant model are used to analyze. The Q-value, quality factor, of inductor is very significant to phase noise. According to the mathematic equations and simulation results, more advanced process technology gives better quality factor of inductor and phase noise. In LC oscillator circuit, the main trade off is between power consumption and phase noise. The phase noise is inversely proportional to power consumption. At last, a new structure that can generate higher negative resistance is proposed. It allows the circuit take less time to stable.