A low power 45dB dynamic-range variable gain mixer in 0.18µm CMOS

This paper presents a novel down-conversion variable gain mixer (VGM) for the L-band DVB application. The proposed VGM adopts an approximated exponential equation for wide range gain variation and double balanced mixer technique for low power consumption. The VGM is simulated in 0.18 mum CMOS technology and measurement results show a gain variation of more than 45 dB and 45 dB-linear range with a linearity error of less than plusmn1 dB. The conversion gain of about 10 dB, P1 dB of -2 dBm and more than 200 MHz flat bandwidth are achieved, while drawing less than 4.2 mA from 1.8 V power supply.