Abstract
This paper describes a CMOS low-noise amplifier (LNA) and a mixer intended for use in Wireless Local Area Network (WLAN) front-end of direct-conversion architecture for the HIPERLAN standard. The circuits were simulated by Spectre using 0.18mm CMOS process at 1.5V supply. The LNA has a forward gain (S21) of 18dB, a noise figure (NF) of 2.6dB while draining 18.8mW at 5.4GHz frequency and –7.6dBm IIP3. The mixer makes use of dynamic matching to improve rejection of second-order intermodulation for the application within a direct-conversion receiver requiring high blocking performance. Its third order and second order input-referred intercept point (IIP3 and IIP2) are 5.2dBm and 54.8dBm, respectively. In addition, the use of dynamic matching can reduce mixer’s flicker noise. This represents 20dBm improvement over a standard Gilbert-cell mixer. The improvement of the noise floor was observed to be 30dB compared to that of a stand Gilbert-cell mixer.