MULTI-MODE LOW NOISE AMPLIFIER WITH TRANSFORMER SOURCE DEGENERATION

摘要

A multi-mode low noise amplifier (LNA) with transformer source degeneration is described. In an exemplary design, the multi-mode LNA includes first, second, and third transistors and first and second inductors. The first transistor has its source coupled to the first inductor, amplifies an input signal, and provides a first amplified signal in a first mode. The second transistor has its source coupled to the second inductor, amplifies the input signal, and provides a second amplified signal in a second mode. The third transistor has its source coupled to the second inductor. The first and third transistors receive the input signal and conduct current through the first and second inductors, respectively, in a third mode. The first transistor observes source degeneration from a transformer formed by the first and second inductors, amplifies the input signal, and provides a third amplified signal in the third mode.