Analysis of performances of a Ka Band reconfigurable satellite antenna Front-End in a broadcasting application over the European territory

This paper describes the results obtained within a contract between the ESA, Politecnico di Milano and Space Engineering, in the section related to the study of an advanced satellite-based system for TV broadcasting in Ka Band. The system is characterized by the possibility of radiating the flux on the served region adaptively, in order to address more power in the zones suffering strong fades (i.e. where it is raining). Weather conditions and expected fades over the service area are assessed with the help of input data coming from the Meteosat satellite and the European Centre of Medium-term Weather Forecasting (ECMWF). Suitable mathematical models are applied, and an optimized distribution of power is evaluated. The paper shortly presents the work procedures of the system, and the performances obtained against an analogue ldquostaticrdquo system, that makes use of the same Front-End and of a climatology-based fixed distribution of power. Results derive from simulations of a 4-years period of work over the European territory.

I. Introduction

The run towards the extensive use of frequencies in the Ka band and beyond in Satellite Telecommunications forces to utilize particular techniques, known as Propagation Impairment Mitigation Techniques (PIMT), to counteract the difficulties posed by the strong atmospheric attenuation. A PIMT of particular interest in satellite applications is the one based on the possibility to control the flux radiated over the served area with the criterion of favouring the sub-regions more affected by adverse weather conditions; this allows an optimum exploitation of the limited power available on board.