The paper presents a novel 5.15[Formula: see text]GHz–5.825[Formula: see text]GHz SiGe Bi-CMOS down-conversion mixer for WLAN 802.11a receiver. The architecture used is based on Gilbert cell mixer, the combination of MOS transistors and HBT BJT transistor device characteristics. The hetero-junction bipolar transistor (HBT) topology is adopted at the transconductance stage to improve power gain and reduce noise factor, and the LO series-parallel CMOS switch topology will be applied to reduce supply voltage and dc power at the switching stage. This mixer is implemented in TSMC 0.35-[Formula: see text]m SiGe Bi-CMOS process, and the chip size including the test pads is 1.175*0.843[Formula: see text]mm2. The main advantages for the proposed mixer are high conversion gain, a moderate linearity, low noise figure, and low power. The post-simulation results achieved are as follows: 14[Formula: see text]dB power conversion gain, [Formula: see text]6[Formula: see text]dBm input third-order intercept point (IIP3), 6.85[Formula: see text]dB double side band (DSB) noise figure. The total mixer current is about 1.54[Formula: see text]mA from 1.4[Formula: see text]V supply voltage including output buffer. The total dc power consumption is 2.15[Formula: see text]mW.
