Electro-formed Front-end at 100 GHz for Radioastronomical Applications

The design of the front-end for a radio-astronomical receiver usually presents notable challenges in terms of large bandwidth and polarization purity and, more recently, for the very high frequencies investigated. In this article, the design of the whole front-end at 100 GHz (horn and backing ortho-mode transducer) is discussed and the critical aspects related to the mechanical structure due to the high frequency of operation are outlined. The article also discusses the aluminum electroforming technology chosen for manufacturing the front-end. Finally, the results of measurements taken on prototypes are shown.