New Methods to Improve Noise Figure of Microwave CMOS LNAs

• Main Authors: Kuo-Jung Sun, 孫國榮
• Other Authors: 王暉
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/90620421544800333472

碩士 === 國立臺灣大學 === 電信工程學研究所 === 93 === The purpose of this thesis is to develop low noise amplifiers employing commercial standard CMOS processes to achieve better noise performance. Two methods to improve the noise characteristics were used to design LNAs. The first approach for improving noise characteristics of the LNA is using the device-size selection to optimize the noise performance. By incorporating the series resistances of the on-chip inductors into the noise optimization procedure, the optimum device size can be selected more appropriately. The 10 GHz LNA has a measured gain 11.25 dB with the noise figure below 3 dB. The second approach for improving noise characteristics of the LNA is using the parallel-resonant technique between the two stages of the cascode LNA, the LNA achieved measured noise figure of 2.5 dB, which is about 0.5 dB noise figure improvement over the first circuit.