Desenvolupament i estudi comparatiu d'oscil·ladors locals per a un radiòmetre en banda L

Disseny d'oscil.ladors de microones en el marc del projecte SMOSops This thesis has been developed in the frame of the ESA scientific mission SMOS. Its purpose is to retrieve data about the soil moisture and ocean salinity in order to track extreme meteorological phenomena and to improve the current models so as to generate global climate change forecasts. The SMOS mission has been providing data since its launch on 2009, which has given the opportunity not only to use the data for the abovementioned purpose, but also some potential performance improvements have been identified to be implemented in a future operative phase known as SMOSops. Among some important improvements the performance of the local oscillator is included, as far as phase drift in temperature is concerned. This has a direct impact in data quality. Thus, the main goal of this thesis is to design a local oscillator to minimise those drifts, and consequently three different architectures of frequency synthesizers have been designed, bread boarded and measured. This thesis presents the theoretical basis for oscillator design, lists the main requirements applicable to the current SMOS local oscillator as well as describes the implemented designs detailing the operational basis for each oscillator. As an output to this investigation and its related activities, a set of new phase performance requirements have been stablished for SMOSops. It?s been demonstrated by means of measurements that one of the designed architectures meets those requirements. Therefore, it is considered as a strong basis for future design of flight oscillators to be used within the SMOSops mission. Este PFC se enmarca en la misión científica de la ESA denominada SMOS. El objetivo de SMOS es recoger información sobre la humedad de la tierra y la salinidad de los océanos a efectos de monitorizar los fenómenos meteorológicos extremos y mejorar los modelos actuales con tal de elaborar previsiones sobre el cambio climático global. El satélite SMOS ha ido proporcionando datos desde su lanzamiento en 2009, hecho que ha permitido no sólo utilizar los datos para el objetivo mencionado anteriormente, sino también se han podido identificar una serie de mejoras a realizar de cara a una fase operativa denominada SMOSops. Uno de los cambios importantes a realizar es la mejora de las prestaciones del oscilador local en términos de variación de fase en temperatura, que impacta directamente en la calidad de los datos obtenidos. El objeti