A Highly Linear D-Band I/Q Receiver With Active Mixer-First Architecture in SiGe Technology

This article presents a highly linear active mixer (Mx)-first <inline-formula> <tex-math notation="LaTeX">$D$ </tex-math></inline-formula>-band quadrature receiver (RX), realized in a 130-nm SiGe BiCMOS technology. The RX consists of two downconversion Mxs, a power divider and a hybrid coupler. The Mxs are designed using a double-balanced Gilbert cell topology with a differential emitter follower output buffer. Given the Mx-first architecture of the RX, a low-noise design approach is adopted for the Mxs, incorporating a noise reduction technique. The measured conversion gain (CG) is 12.7 dB at 140 GHz with a remarkable 3-dB CG RF bandwidth of 40 GHz, from 125 to 165 GHz, at a fixed IF frequency of 1 GHz. The RX exhibits a measured minimum double-sideband (DSB) noise figure (NF) of 8.2 dB at 140 GHz and better than 9-dB DSB NF over the 3-dB RF bandwidth. The input-referred 1-dB compression point is measured to be −3.5 dBm, which demonstrates a simultaneous leading-edge performance in terms of linearity and noise. The total occupied chip area is 0.67 mm2 including the pads and baluns, while the effective core area is only 0.23 mm2. The proposed RX consumes 34 mW from a 3-V supply excluding the power consumption of the common-collector (CC) buffers.