QUBIC VII: The feedhorn-switch system of the technological demonstrator

We present the design, manufacturing and performance of horn-switch system developed for technological demonstrator QUBIC (the $Q$\&$U$ Bolometric Interferometer Cosmology). This is constituted 64 back-to-back dual-band (150\,GHz 220\,GHz) corrugated feed-horns interspersed with mechanical switches used to select desired baselines during instrument self-calibration. manufactured horns in aluminum platelets milled by photo-chemical etching mechanically tightened screws. The are based on steel blades that open close wave-guide between operated miniaturized electromagnets. also show current development status feedhorn-switch full instrument, an array 400 assemblies.