Comparison of LNAs fabricated in 65-nm CMOS GP and LP processes for the Square Kilometre Array

Abstract

In this work two 0.7-1.4GHz room-temperature 65nm CMOS low noise amplifiers (LNAs), designed for the Square Kilometre Array (SKA) radio telescope receiver, are compared. One LNA was fabricated with low-power (LP) transistors whereas the other, otherwise identical LNA, was fabricated with general-purpose (GP) transistors. As shown there are electrical and noise performance differences between the two circuits. The GP-LNA achieves better noise temperatures (∼22K) at the upper band edge whereas the LP-LNA has a higher gain. The GP-LNA is a marginally better option for the SKA due to better S₁₁ and lower noise temperatures at the upper frequency range.