"Front-end design at 22GHz for the Gregorian focus of the new Sardinia Radio Telescope."
L. Cresci, L. Lucci, S. Orfei, V. Natale, R. Nesti, D. Panella, G. Pelosi, L. Rossi
IRA
In this contribution the design of the whole passive front-end of the 22GHz cooled receiver for the Sardinia Radio Telescope (SRT) is presented. It has been developed in the framework of the Faraday project. It comprises a corrugated feed horn, a directional circular waveguide coupler and a polarizer. A quite original design approach has been adopted since these devices have been optimized for high performances in the 19-26GHz band. Fabrication and measurement aspects are also discussed; some prototypes of the above components have been produced and tested highlighting very good agreement with expected electromagnetic behavior. Furthermore the effects of the beam in the sky due to the above front-end feeding the Gregorian dual-mirror configuration of the SRT radio telescope are analyzed.