A 77-GHz MMIC power amplifier driver for automotive radar

A SiGe 77 GHz power amplifier driver combining two three-stage amplifier MMIC is reported. The measured small signal gain of the chip varies from 16 to 18 dB from 75 GHz to 80 GHz with 3.37 dBm saturated output power at 77 GHz. The 3 dB bandwidth is between 70 and 82 GHz. The maximum small signal gain is around 17.9 dB at 79 GHz. This chip is fabricated using 0.25 μm SiGe BiCMOS process. The power divider and combiner improve the linearity and relax the output power requirement of the amplifier unit and therefore this circuit is suitable to be used as a driver in the 77/79 GHz automotive radar transmitter.