LADU, AdelaideAdelaideLADUMONTISCI, GIORGIOGIORGIOMONTISCIVALENTE, GiuseppeGiuseppeVALENTENAVARRINI, AlessandroAlessandroNAVARRINIMARONGIU, PasqualinoPasqualinoMARONGIUPISANU, ToninoToninoPISANUMazzarella, GiuseppeGiuseppeMazzarella2020-07-242020-07-2420170048-6604http://hdl.handle.net/20.500.12386/26615A 180° hybrid and a directional coupler to be employed in the P-band cryogenic receiver of the Sardinia Radio Telescope are proposed in this work. An in-depth study of the issues related to the use of microwave components for cryogenic radio astronomy receivers is carried out to select the best suited technology and configuration. As a result, a planar fractal 180° hybrid configuration available in the literature has been optimized aiming to increase the operating bandwidth in order to comply with the design specifications of the application at hand. A coupled line directional coupler with weak coupling and high isolation, used to calibrate the receiver chain, is cascaded to the 180° hybrid and realized in the same layout. The final device, consisting of the 180° hybrid and the directional coupler, has been manufactured and tested at the cryogenic temperature of 20 K, showing a good agreement between experimental results and predicted performance.STAMPAenArticle10.1002/2017RS0062922-s2.0-85020389371000405996500005https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017RS0062922017RaSc...52..757LING-INF/02 - CAMPI ELETTROMAGNETICI