Análisis y propuesta de diseño del subsistema de antena de la carga útil de un CubeSat para constelaciones de comunicaciones en órbita LEO

Abstract

Space communications industry is emerging as a very attractive sector in order to provide high capabilities demand services. These communications are made up of large constellations currently set up by small satellites. CubeSats belong to the category of pico-satellites and they are deployed in low Earth orbit (LEO) which provides low latency and reduced launch costs due to their restricted sizes. However, CubeSats has their own limitations because of their constitution, the power available is limited and the used to emit in UHF and VHF-band which implies low data rates achieved. This Bachelor Thesis addresses the proposal and study of an antenna in Ka-band (28 GHz and 38 GHz) as part of the CubeSat payload communications subsystem. Operate in Ka-band offers high bandwidth as well as a higher gain antenna which contributes to higher rates. The antenna design is based on the use of a flat lens that improves the directivity of a choke horn. For this purpose, several lens models have been properly characterized. The obtained results show a 20 dBi directivity at 28 GHz and a 22 dBi directivity at 38 GHz, with a maximum estimated throughput of 60 Mbps and 140 Mbps under reasonable conditions with new and high modulation and codification schemes, at altitudes of 1100 km (LEO) and 340 km (VLEO) respectively. These outcomes prove the feasibility of using CubeSats for this type of constellation, since with a suitable terrestrial and spatial infrastructure, they are able to support the demand for broadband services.