I. Introduction
GaAs based Monolithic Microwave Integrated Circuits (MMICs) offer several advantages over the other forms of microwave technology. These includes reduced size and weight, enhanced system performance from inclusion of several functions on a single circuit, wider frequency bandwidth performance from the reduction of parasitic in discrete device packaging, enhanced reliability and cost reduction. These properties make it the technology of choice especially in space and defence industries. Looking at the advantages in terms of improved performance and reduced weight and volume, space qualified MMICs have been used in the realization of advanced communication payloads of Indian satellites such as GSAT and INSAT. MMIC based Ku band Automatic Level Control-Driver Amplifier (ALC-DA) subsystem has been flown in GSAT-16 spacecraft and is planned to be used in future missions of GSAT-11 and GSAT-18 as well.