Available at: http://digitalcommons.calpoly.edu/theses/1116
Date of Award
MS in Electrical Engineering
Dr. Dennis Derickson
The beginning of this thesis provides an overview of the heritage UHF Communication System design flown on CP2, CP3, CP4, CP5, and CP6, summarizing previous analysis of its performance, and providing the justification for a complete system re-design. High level requirements for the new UHF System are defined, and a trade study is performed on state-of-the-art single chip transceivers, low noise amplifiers, and transmit power amplifiers. These components are then designed into a functional communication system, with key components analyzed for proper impedance matching and performance characterization compared to expected datasheet values. Next, the system as a whole is characterized for its receive sensitivity, and issues are documented that arose during this system testing. Performance of the new system demonstrate the dramatic improvement over the heritage design, but highlights the importance of a proper antenna design. Several charts produced from a simplified link budget using empirical data provide expected data rates given different orbital altitudes and transmit powers. Lastly, a brief discussion on future work for turning the system into a ground station, and the potential for dynamic on-orbit data rates to maximize the data down while minimize power requirements is discussed as future work.