Digital TT&C transmitter development

• Grant number: 16/50175-0
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: November 01, 2017
• End date: October 31, 2020
• Field of knowledge: Engineering - Aerospace Engineering - Aerospace Systems
• Agreement: FINEP - PIPE/PAPPE Grant
• Principal Investigator: Gustavo Ribeiro Alves
• Grantee: Gustavo Ribeiro Alves
• Company: Atmos Sistemas Ltda
• City: São Paulo

Abstract

The Brazilian National Institute for Space Research (INPE) conducts since the 80's satellite development programs, worth of mention MECB program (Complete Brazilian Space Mission), CBERS (China-Brazil Earth Resources Satellite) and PMM (Multi-Mission Platform). Since then, INPE has already successfully launched several remote sensing satellites in low orbit, with missions such as imaging, data collection and other scientific experiments. These satellites were built in cooperation with the national industry and have high local content, creating high technology knowledge. The TT & C transponder installed on these satellites has the function of receiving commands from earth stations and send back the satellite telemetry data. Its operation includes receiving and sending back the tones used to measure the distance from the satellite to the earth station (ranging tones). Operation of the transponder is in the S-Band, with two separate sub-bands to uplink (earth station - satellite) and downlink (satellite - ground station). To date, all TT & C transponders used in satellites built by INPE used analog technology. There is a trend on radio devices (including non-spatial) towards digitization of data from an intermediate frequency, performing tasks from this point (demodulation, filtering, etc.) digitally. On radio transmitters, the signals are digitally generated up to higher frequency, being transformed into analog signals at a later stage. To perform the operations digitally up to an intermediate frequency, are used programmable devices such as FPGAs ("Field Programmable Gate Array"). Using the same hardware, several different operations can be performed, making the systems that use these devices very flexible from the application point of view. This work proposes the development of an engineering model for a digital transmitter TT & C for future space applications. (AU)