77GHz Low Noise Sub Block MMICs with 120 nm In0.4AlAs/In0.35GaAs Metamorphic HEMTs

Abstract

77 GHz CPW low noise sub block (LNB) MMICs, which are consisted of a 3 stage LNA and a resistive mixer, have been successfully developed by using 120nm In0.4AlAs/In0.35GaAs metamorphic high electron mobility transistors (MHEMTs). The devices show an extrinsic transconductance gm of 760 mS/mm, a maximum drain current of 750 mA/mm, and a gate drain breakdown voltage of -8.5 V. A cut-off frequency (fT) of 172 GHz and a maximum oscillation frequency (fmax) of over 300 GHz are achieved. The LNA exhibited small signal gain of 19.2 dB and conversion gain of the LNB is measured to be 11 dB at 500 kHz IF