On antenna systems for space applications

Voorbeelden van satelliet projecten van de Europese Ruimtevaart Organisatie ESA (European Space Agency) worden in globale zin beschreven met referenties en met aandacht voor de antenne aspecten, met name satellieten voor wetenschappelijke en aard-observatie toepassingen. De beperkingen ten aanzien van beschikbaar vermogen op de satelliet, met daarbij strenge eisen voor mass en voor de toelaatbare temperaturen, dat alles maakt het ontwikkelen en realiseren van nauwkeurige antennes voor de ruimtevaart tot een interessante en veeleisende bezigheid. Daarbij komt ook nog, dat bijvoorbeeld microgolf instrumenten met de sensoren (de antennes) uiterst nauwkeurig moeten kunnen meten. Examples of satellite projects accomplished by the European Space Agency (ESA) are broadly summarized with references and with attention to antenna aspects. Antennas are discussed for scientific or remote sensing applications. Limited power resources onboard the satellite, mass constraints and harsh space environmental factors dictate requirements, which often can only be satisfied after accurate efforts for design, realization and testing processes of antennas. Gain, coverage or pattern properties and polarization requirements must be satisfied for antennas. Requirements can be more demanding for microwave instrument antennas since instruments must measure accurately in absolute sense. Accurate knowledge of radiation behavior (vector behavior) is needed. High power transmission and very low power reception can dictate requirements for passive intermodulation (PIM). Multipaction aspects must be addressed to assure that no breakdown occurs because it might jeopardize antenna functionality. Quasi-optical techniques for high power applications are addressed in these proceedings. This paper describes with references, that there is some synergy in antenna development with the field of quasi-optics and high power rf-engineering; that there are developments and application scenarios for tools and techniques for antennas, which could be used for other applications discussed elsewhere in these proceedings and vice-versa