A 19GHz VCO downconverter MMIC for 77GHz automotive radar frontends in a SiGe bipolar production technology

Abstract

A VCO based 19 GHz downconverter is presented, which is fully integrated in a 200 GHz f_T SiGe production technology. The circuits, a voltage controlled oscillator (VCO), a buffer, a gilbert cell mixer and a prescaler have been designed fully differentially. The VCO is optimized for low phase noise. The oscillator operates at typically 19 GHz and is used to downconvert the by-4-divided signal of a 77 GHz fundamental oscillator. The conversion gain of the mixer is about -7 dB and the input referred 1 dB compression point is about +1 dBm. Phase noise of the VCO is -115 dBc/Hz at 1 MHz offset and power dissipation is 750 mW operating at a +5.5 V supply.