Design and Implementation of Voltage Control Oscillator

• Main Authors: Chih-Hsien Shen, 沈致賢
• Other Authors: Shey-Shi Lu
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/64995750657177804652

碩士 === 國立臺灣大學 === 電子工程學研究所 === 91 === In this work, the principles and verification of basic LC tank VCO are introduced. Several design theorems has been tested and verified by the experiment results. In chapter 1 and 2, we introduce the specifications a VCO should achieve. A viewpoint from the system requirement is brought up to formulate what the critical term is and to avoid wasting efforts. How these conditions tradeoff with each other is also introduced. In chapter 3, we quote two methods to predict the phase noise, the most important performance which is the most difficult to content. The sources of phase noise are classified into three basic parts efficiently: resonant tank, differential pair and the tail (or top) current source. Base on knowledge stated above, we bring up some suggestions helping design the VCO in chapter 4. An unequivocal method of choosing on-chip inductor using NCR analysis is discussed. Switched cap-array combined with analog varactor obtains the effective large KVCO without worse phase noise. Filtering technology lower the noise factor approaching its funda- mental minimum. It is also the first time we apply the phase noise theory on GaAs HBT technology. Finally, the other requirements such as driving capability, impedance isolation, and quadracture phase are fulfilled by the output stages.