An Ultra-Wide Tuning - Range VCO

• Main Authors: Su, Kuo-Cheng, 蘇國政
• Other Authors: Tarng, Jenn-Hwan
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/67957547754878186599

碩士 === 國立交通大學 === 電信工程研究所 === 98 === In order to increase the frequency tuning range of a voltage-controlled oscillator (VCO), single-ended active inductors are usually replaced by differential active inductors, which need less number of transistors to yield smaller parasitic capacitance. However, the differential active inductors lower the overall current and may lead VCO’s negative resistance to be out of function, which still limits the frequency tuning range. In this thesis, a feedback resistor is added to limit the minimum conductance of the active inductor to achieve an ultra-wide tuning range VCO of 5 GHz. The proposed circuit is implemented by the TSMC 0.18μm 1P6M process technology, and the measurement result of the proposed VCO can be tuned from 0.5 GHz to 5.6 GHz. Its frequency tuning range is 165%. The phase noise ranges from -94 to -99 dBc/Hz at a 1-MHz offset. The die area of the VCO is 175 x 170 .