UHF-VHF Cubesat Antennas Design

Abstract

The main objective of this Thesis is to understand the antennas used in Cubesats (a satellite type becoming very popular among universities for teaching their students space related skills while improving their background) and to develop a prototype for future development in the GranaSAT mission. This Thesis aims to be a future reference for students developing Cubesat antennas for GranaSAT. For start, a brief introduction on antenna theory will be made for readability purposes, introducing all the terms and the fundamental parameters necessary for understanding the Thesis like scattering parameters, standing wave ratio, input impedance of an antenna, an analysis of the radiation pattern , directivity, polarization and a brief analysis on considerations for space communications. In space communications it is fundamental to achieve circular polarization because of the effect of the ionosphere in the electromagnetic waves. The strong electric charge can change the polarization in a way that is impossible to predict, so at the ground station it is mandatory to have a circular polarized antenna. After this introduction on antenna matters, an analysis of the solutions used in the previous mission will be developed, specially considering different approaches, as well as the study of the State of the Art solution. A popular receiving antenna called Quadrifilar Helix Antenna will be simulated with the Feko software in order to understand its behaviour.

Este proyecto tendrá como objetivo la comprensión de las antenas usadas en los Cubesats, un tipo de picosatélite desarrollado mayormente en universidades. El trabajo se concentrará en el análisis de sistemas usados en misiones previas dentro del ámbito de los picosatélites, recepción de señales de otros satélites y diseño de un prototipo de modelado de antenas para la misión GranaSAT.