MULTI-LINEARITY MODE LNA HAVING DEBOOST CURRENT PATH

PROBLEM TO BE SOLVED: To provide a low noise amplifier (LNA) having a very high third-order input intercept point (IIP3) as well as a low noise factor (NF), high gain and a low current consumption.SOLUTION: A modified derivative superposition (DS) low noise amplifier (LNA) 222 includes a main current path 320 and a cancel current path 322. Third-order distortion in the cancel path is used to cancel third-order distortion in the main path. In one novel aspect, there is a separate source degeneration inductor 306, 308 for each of the two current paths, thereby facilitating tuning of one current path without affecting the other current path. In a third novel aspect, the cancel current path and/or a deboost current path is programmably disabled to reduce power consumption and improve a noise figure in operational modes that do not require high linearity.