The Cosmic Microwave Background Polarization

Abstract | The polarization of the Cosmic Mi-crowave Background is one of the most powerful tools for cosmological investigations. In spite of its importance, it is very faint and can be as low as 10¡7 of the total signal. In general, state of the art microwave passive devices do not match the require-ments for a clean detection of this signal. Thus, a signi¯cant e®ort has to be spent analyzing the sys-tem, identifying critical components and developing new devices with higher performances. This paper presents the case of the SPOrt experiment, where the system has been carefully analyzed and most of the passive devices have been developed with the aim of keeping systematics lower than the signal to be detected