Impact of high frequency correlated noise on SiGe HBT low noise amplifier design

This paper investigates the impact of high frequency noise correlation on SiGe HBT LNA design. With correlation, simultaneous noise and impedance match is found to continue to hold approximately. However, a larger size and hence a higher biasing current are required for noise matching. The actual noise figure (NF) of LNAs designed without considering noise correlation is also investigated. Further investigation shows that a size considerably smaller than noise matching size is more preferable, as it produces high gain, high linearity and NF only slightly higher noise figure at much smaller power consumption.