A W-band ultra low noise amplifier MMIC using GaAs pHEMT

This paper presents a newly developed 76 GHz three-stage LNA for automotive radar systems. The LNA utilizes multi band rejection filter type stabilizing circuits to achieve good noise figure together with good stability. The operating bias condition was carefully chosen to obtain low temperature dependence of gain. As a result, the LNA delivers a noise figure of 3.5 dB typically, small temperature dependence of gain of -0.016 dB/deg.C and high return loss using a highly conventional 0.19 /spl mu/m T-shaped gate AlGaAs/InGaAs/GaAs pHEMT process.