A compact 2.4/5.2-GHz CMOS dual-band low-noise amplifier

This letter presents a fully integrated 2.4/5.2-GHz dual-band low-noise amplifier (LNA) for WLAN applications. By switching the input transconductance and the output capacitance, the narrow-band gain and impedance matching are achieved at the 2.4-GHz and the 5.2-GHz frequency bands. Using a standard 0.18-μm CMOS process, a compact dual-band LNA with a chip size comparable to a single-band one is realized in the proposed topology for a minimum hardware cost. The fabricated circuit exhibits gains of 10.1dB and 10.9dB, and noise figures of 2.9dB and 3.7dB at the two frequency bands, respectively.