Silicon bipolar up and down-converters for 5-GHz WLAN applications

A dB-linear variable-gain up-converter and an image-reject down-converter for 5-GHz wireless LAN applications were implemented in a 46-GHz-f_T silicon bipolar technology. The up-converter exhibits a 13-dB power gain and an output 1-dB compression point of 6 dBm. It adopts a digital pre-distortion technique to achieve a linear-in-dB gain characteristic with a dynamic range of 30 dB. The down-converter exhibits a 4-dB noise figure and a power gain of 23 dB. By using a 1-bit gain control it also achieves an input 1-dB compression point of -14 dBm. An image-rejection approach based on monolithic passive notch filters provides an image rejection ratio higher than 60 dB.