DESIGN AND SIMULATION OF S-BAND MICROWAVE AMPLIFIER FOR SATELLITE COMMUNICATIONS SYSTEM

This paper presents a novel design of S-band monolithic microwave integrated circuit (MMIC) amplifiers based on GaAs MESFET HFET-1102 transistors used in radiofrequency (RF) and microwave communications systems. Based on the Chebyshev gain response, an analytical method is used to design a two-stage lumped microwave amplifier. The matching networks constituted by lumped elements are transformed into T inductive networks, and the resulting amplifier is optimized using RF simulator software. In the following step, the lumped optimized amplifier is transformed into a distributed amplifier and implemented on Rogers TMM3 substrate largely used in microwave circuits. The final MMIC amplifier is stable in the frequency band (2-4 GHz), and excellent performances are obtained in terms of very high gain, reaching a peak of 35 dB, low input (S11) and output reflection (S22) coefficients, and very good output/input isolation (S12). For its RF characteristics, the proposed MMIC amplifier presented in this work is very suitable for space telecommunications in low earth orbit (LEO) satellites onboard receivers.