Design of a Low-Power Dual-Band VCO and a 5-GHz Integer-N Frequency Synthesizer

• Main Authors: Yun-Chung Chen, 陳韻中
• Other Authors: Sao-Jie Chen
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/51889049397457071606

碩士 === 國立臺灣大學 === 電子工程學研究所 === 99 === A frequency synthesizer plays an important role in a communication system. In RF transceivers, frequency synthesizers are used as local oscillators to up- or down-convert the signal. A voltage-controlled oscillator (VCO) is an essential component of a frequency synthesizer, used to generate the output signal. This Thesis is separated into two parts: a low-power dual-band VCO design and a 5-GHz integer-N frequency synthesizer design. In order to integrate multi-standards, we propose a dual-band VCO (DVCO) which is able to generate 2.4GHz and 5GHz signals simultaneously, and uses current-reuse technique to reduce the power consumption. The core DVCO, designed in TSMC 1P6M 0.18-um process, consumes 3.12mW with a 1.2-V supply. In the second part, the Thesis reports the design of a 5-GHz integer-N frequency synthesizer in TSMC 1P6M 0.18-um process. In this design, a divided-by-2 is proposed to reduce the power consumption, and a charge pump circuit is proposed to improve the linearity. The total power consumption of this synthesizer is 19.8 mW with a 1.8-V supply, and the settling time is 20 us at 20MHz frequency jumping.