  In this paper we describe QUBIC, an experiment that will observe the
polarized microwave sky with a novel approach, which combines the sensitivity
of state-of-the art bolometric detectors with the systematic effects control
typical of interferometers. QUBIC unique features are the so-called
"self-calibration", a technique that allows us to clean the measured data from
instrumental effects, and its spectral imaging power, i.e. the ability to
separate the signal in various sub-bands within each frequency band. QUBIC will
observe the sky in two main frequency bands: 150 GHz and 220 GHz. A
technological demonstrator is currently under testing and will be deployed in
Argentina during 2019, while the final instrument is expected to be installed
during 2020.
