A High-gain Cmos Lna for 2.4/5.2-ghz Wlan Applications

This paper describes a high-gain CMOS low-noise amplifier (LNA) for 2.4/5.2-GHz WLAN applications. The cascode LNA uses an inductor at the common-gate transistor to increase its transconductance equivalently, and therefore it enhances the gain effectively with no additional power consumption. The LNA is matched concurrently at the two frequency bands, and the input/output matching networks are designed with two notch frequencies to shape the frequency response. The dual-band LNA with the common-gate inductor is designed, implemented, and verified in a standard 0.18-μm CMOS process. The fabricated LNA which consumes 7.2mW features gains of 14.2 dB and 14.6 dB, and noise figures of 4.4 dB and 3.7 dB at the 2.4-GHz and 5.2-GHz frequency bands, respectively. The proposed LNA demonstrates a 4.9–7.8 dB gain enhancement compared to conventional cascode LNAs, and the chip size is 1.06mm× 0.79 mm including all testing pads.