GSM and DCS SiGe BiCMOS mixer ICs with wide LO power range

GSM and DCS mixer ICs operating with the LO drive ranging from -35 dBm to -5 dBm and the supply voltage ranging from 2.4 V to 3.6 V are reported in this paper. The measured conversion gain and noise figure of the GSM mixer are 8.9 dB and 10.2 dB, respectively, and those of the DCS mixer are 8.5 dB and 10.9 dB. The GSM mixer IIP3 is 1 dBm, whereas the DCS mixer IIP3 is 4 dBm. A high-gain multistage LO driver and bias currents insensitive to supply voltage variation facilitate the mixer application for commercial mobile terminals. The GSM and DCS mixers were designed and fabricated using 0.25-/spl mu/m SiGe BiCMOS process. An integrated GSM (DCS) mixer, comprising a Gilbert core, an LO driver, a limiter, an IF buffer and bias circuits, consumes 28.5 mA from a 3-V battery. The SiGe BiCMOS mixers feature comparable IIP3, higher gain, and lower noise figure than do our previously fabricated Si BiCMOS mixers based on the same topology, and also consume 29% less power.