Architecture development and testing for the engineering model of SUTS satellite communication system

Abstract

This bachelor’s thesis presents the development and testing of the communication subsystem for the Strategic Upgrades Test Satellite (SUTS), a 3-unit PQ picosatellite developed by the Estonian Student Satellite Foundation. The primary goal was to design an engineering model of the UHF communication system that meets the constraints of small satellite architecture while maintaining reliability and regulatory compliance. The system, which operates in the 435–438 MHz amateur band using Gaussian Frequency Shift Keying (GFSK) modulation, was designed with a focus on simplicity, efficiency, and space optimization by omitting a dedicated MCU and instead relying on control via the main Command and Data Handling System (CDHS). Key components include the Silicon Labs Si4468 transceiver and the GRF5504 power amplifier. The thesis provides an in-depth analysis of the architecture, link budget, PCB layout, and RF chain design, as well as a comprehensive suite of performance tests including gain, efficiency, thermal tolerance, out-of-band emissions, and receiver sensitivity. The results validate the communication subsystem’s performance and inform further development toward a flight-ready model.