Design And Implementation Of Front-end Of Demodulator For Satellite Communication System

With the rapid development of satellite communication technology and SoftwareRadio technology, various problems associated with the technologies above have becomeresearch hotspots. The design of demodulator of communication receiver is one of the keybarriers among those problems. There is a possibility of wide application and researchvalue if a universally-used demodulator capable of receiving different intermediatefrequency signals is designed, based on existing RF analog front-end frameworks.Starting from the design background, this paper describes the basic structure of thesatellite communication system receiver, accordingly, it clearly shows the overall structuraldesign of a demodulator, and analyzes circuit features of front-end part of the IF amplifierand ADC of a demodulator. First, after analyzing of the main technical indicators of theamplifier, the design of broadband and controllable gain amplifier based on ADI’s amplifierchips is completed, and gain flatness improves by using digital AGC, thus it basically meetsthe design requirements after simulation test.ADC is a key component of interface between analog system and digital system, withthe development of signal processing technology and communication industry, ADCdevices have been widely used, and gradually developed in two directions, high-speed andhigh-precision. This paper ultimately gives the reader a final PCB design by hammering outan ADC which meets the design specifications after analyzing its structure andperformance.