A concurrent dual-band LNA for 2.4 GHz and 5.2 GHz application based on active inductor technic

Abstract

A concurrent dual-band low-noise amplifier (DB-LNA) based on active inductors was designed to operate at 2.4 GHz and 5.2 GHz to meet IEEE 802.11 n standards. The conventional common source cascode topology without the source degeneration inductor is implemented in the gain control stage. Input impedance matching is achieved with a single-path circuit resonating at two distinct frequencies, while output matching is accomplished using band-pass and band-stop filters. Active inductors replace traditional passive inductors to reduce layout area, and their high Q factor minimizes power consumption. Furthermore, gate noise is suppressed with a capacitor between source and gate in the input stage. The results show that the proposed DB-LNA has gains of 17.2 dB and 12.0 dB at 2.4 GHz and 5.2 GHz, respectively, with noise figures of 3.5 dB and 4.7 dB. The $S_{11}$ and $S_{22}$ of the DB-LNA are both less than −10 dB at both frequency bands. The 1 dB compression points are −23.9 dBm at 2.4 GHz and −18.7 dBm at 5.2 GHz, with third-order input intercept point values of −13.1 dBm and −8.3 dBm, respectively. The total power dissipation is 15.72 mW with a 1.2 V supply, and the layout area is 0.32 mm${}^2$.