A Single-Ended Fully Integrated SiGe 77/79 GHz Receiver for Automotive Radar

A single-ended 77/79 GHz monolithic microwave integrated circuit (MMIC) receiver has been developed in SiGe HBT technology for frequency-modulated continuous-wave (FMCW) automotive radars. The single-ended receiver chip consists of the first reported SiGe 77/79 GHz single-ended cascode low noise amplifier (LNA), the improved single-ended RF double-balanced down-conversion 77/79 GHz micromixer, and the modified differential Colpitts 77/79 GHz voltage controlled oscillator (VCO). The LNA presents 20/21.7 dB gain and mixer has 13.4/7 dB gain at 77/79 GHz, and the VCO oscillates from 79 to 82 GHz before it is tuned by cutting the transmission line ladder, and it centres around 77 GHz with a tuning range of 3.8 GHz for the whole ambient temperature variation range from -40degC to +125degC after we cut the lines by tungsten-carbide needles. Phase noise is -90 dBc/Hz@l MHz offset. Differential output power delivered by the VCO is 5 dBm, which is an optimum level to drive the mixer. The receiver occupies 0.5 mm
²
without pads and 1.26 mm
²
with pads, and consumes 595 mW. The measurement of the whole receiver at 79 GHz shows 20-26 dB gain in the linear region with stable IF output signal. The input P
_1dB
of the receiver is -35 dBm.