The QUIJOTE CMB Experiment is an ongoing experiment started in November 2012, and led by Rafael Rebolo López, with the goal of characterizing the polarization of the cosmic microwave background (CMB) and other galactic and extragalactic emission in the frequency range 10 to 40 GHz, at angular scales of 1°.

[1] These measurements will complement at low frequency and correct from galactic contamination those obtained by the Planck satellite from 2009 to 2013.

The primordial matter density fluctuations that originated the present structure of the universe left imprinted spatial variations in the CMB radiation.

The first QUIJOTE-CMB telescope (QT1), in operation since November 2012, has two instruments which can be exchanged in the QT1 focal plane.

The second QUIJOTE-CMB telescope (QT2), in operation since 2014,[3] will house a third instrument (FGI) with 31 polarimeters working at 40 GHz.