Methodology to calibrate S-band dish antennas for micro-satellite missions

The purpose of this Master's Thesis project is to investigate the validity of a methodology to calibrate Alma Mater Ground Segment S-Band Dish Antenna based on LDR and a low-cost project. Considering the beamwidth aperture of S-Band 3.2 deg, the angular requirement is an accuracy of at least 1 deg. Implementation of LDR can achieve this task, but a test bench to validate this option has to be set up. The activity presents a hard challenge, since antenna calibration is an uncharted path; there is poor coverage of techniques in the literature, most of it is very old, dating back to the 1960s, and any found design lacks in details. However, the need of the AMGS is a cheap, simple design, that allows calibration during daylight. The work is part of a wider effort for upgrading the AMGS, aimed to the accomplishment of ESA mission ESEO. The whole Calibration Plant, hardware and software, is described in detail, with the aim of giving the possibility to future readers to reproduce and/or improve. The first aspect investigated is the feasibility study, followed by the implementation of the project itself. Devices, components, tools and consumables are all listed in the bill of materials, which includes the LDR box, additive-manufactured. Electronic hardware components and the hand-made realisation of some of them is described just before the illustration of all the parts of the Calibration Software, developed in MATLAB and Arduino. Subsequently, validation and experimental tests are reported, together with graphs. Ultimately, the field tests are described and analysed, followed by some hints for future developments and improvements. Results show that the developed concept for antenna calibration is validated in laboratory environment, while field tests reveal to be prone to environmental noise, thus suggesting for alternative design solutions.