0.4–6 GHz,17-dBm B1dB, 36-dBm IIP3 channel-selecting, low-noise amplifier for SAW-less 3G/4G FDD receivers

A channel-selecting, low-noise amplifier (CSLNA) is presented that meets the requirements for a SAW-less diversity path receiver in frequency-division duplexing (FDD) cellular systems. An N-path filter is incorporated into the LNA feedback network to tune from 400 MHz to 6 GHz. The proposed CS-LNA creates close-in stopbands around the passband to suppress transmit (TX) blockers up to 17 dBm. This work reports an out-of-band (OOB) IIP3 of 36 dBm and IB IIP3 of 10 dBm with the maximum rejection larger than 60 dB. To the author´s knowledge, this is the highest blocker rejection, power-handling capability and IIP3 for an LNA that is tunable over more than a decade.