Cosmic microwave background polarization receivers: QUIJOTE experiment

The QUIJOTE (QUI JOint TEnerife) Experiment will characterize the polarization of Cosmic Microwave Background radiation and other galactic and extragalactic emissions in the frequency range from 10 to 30 GHz, and at large angular scales. The polarimeter receivers at 11,13, 17, 19 and 30 GHz are radiometers based on broadband waveguide rotating polar modulators and broadband orthomode transducers. High sensitivity of polarimeters is achieved with very low noise cryogenic amplifiers (Noise temperature <; 15 K in 11-19 GHz channels and <; 20 K in 30 GHz channel). Subsystems test results and integration measurements of front-end and back-end units show wideband operation in all channels.