A 225-265 GHz I-Q Receiver in 130-nm SiGe BiCMOS for FMCW Radar Applications

This letter reports a compact-size 225-265 GHz quadrature receiver (RX), consisting of a low-noise amplifier (LNA), a power divider (PD), two down-conversion fundamental mixers, and an IQ generator, in a 130-nm SiGe BiCMOS technology with $f_{T}$ /f $_{max}$ of 300/500 GHz. The measured peak value of the down-conversion power gain is 20.6 dB at 240 GHz without IF amplification, and it achieves a 3-dB RF bandwidth of 40 GHz from 225 to 265 GHz. The measured minimum single-sideband (SSB) noise figure (NF) is 13.2 dB at 240 GHz and better than 14.2 dB along the 3-dB RF bandwidth. The amplitude and phase imbalances of the IF output signals were measured as less than 1.7 dB and 2,degrees, respectively, over the frequency range of interest. The RX circuit draws a current of about 40.5 mA from a single-supply of 3.3 V. It occupies a total area of 0.42 mm(2) (0.97 mm x 0.43 mm), and the effective area is about 0.14 mm(2), excluding the pads and Marchand baluns placed for on-wafer probing.