Advanced high performance MMICs for satellite transponder

This paper presents the design and measured results of a high performance multifunction GaAs MMIC chipset for C and extended-C band receiver and channel amplifier for communication satellite onboard systems. All MMICs, i.e., low noise amplifier (LNA), double balanced mixer (DBM), variable gain amplifier (VGA) and amplifier with 4-bit digital attenuator are realized using 0.2μm GaAs PHEMT process. The goal is to reduce chip count and off chip components while achieving best system performance. Key features of these circuits are low noise, excellent gain and gain flatness, LO harmonic rejection and good linearity with gain control. In design, special attention was given to unconditional stability and good matching. This makes all MMICs cascadable, which eliminates isolators in system design. These MMICs provide a simple, ultra miniature (90gm), three-chip all MMIC solution to satellite on board receiver design with better RF performance (60dB gain with 1.2dB noise figure in full 5.6GHz-7.1GHz band). As the designs use same MMIC process, in next step, these MMICs can be combined to form a single chip receiver with same performance. MMIC chips are designed for two standard packages with chip size 2.6mm × 1.6mm and 2.6mm × 2.0mm.