A GaAs HEMT MMIC chip set for automotive radar systems fabricated by optical stepper lithography

Abstract

A production oriented GaAs HEMT MMIC chipset for a 77 GHz FMCW automotive radar system is reported. It differs mainly in two aspects from the GaAs MMIC solutions described earlier: (1) 0.12 /spl mu/m gatelength PHEMTs are fabricated by optical stepper lithography, (2) a coplanar design is used. A fully passivated PHEMT fabrication process is reported with current-gain and power-gain cutoff frequencies exceeding 115 and 220 GHz, respectively. The design and performance of the chipset consisting of four different MMICs (VCO, harmonic mixer, transmitter, receiver) is described. The great potential of this MMIC approach to meet all system requirements of an automotive radar sensor in a cost effective and production oriented way is shown.