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

CAVALIERE, F.; BATTAGLIA, P.; BURKE, D.; FRANCESCHET, C.; MAFFEI, B.; MASI, S.; PEZZOTTA, F.; TORCHINSKY, S.A.; ADE, P.; AMICO, G.; AUMONT, J.; BAÙ, A.; MENNELLA, A.; BERGÉ, L.; BATTISTELLI, E.S.; BIGOT-SAZY, M.-A.; D'ALESSANDRO, G.; BUNN, E.; GRANDSIRE, L.; CHAPRON, C.; MANZAN, B.; COLUMBRO, F.; O'SULLIVAN, C.; DE LEO, M.; PIAT, M.; DUMOULIN, L.; VIGANÒ, D.; FERREYRO, L.P.; ALBERRO, J.G.; GANGA, K.M.; ARNALDI, L.H.; GASPARD, M.; AZZONI, S.; GIARD, M.; BÉLIER, B.; GÓMEZ BERISSO, M.; BERNARD, J.-PH.; HAMPEL, M.R.; BONAPARTE, J.; INCARDONA, F.; BUZI, D.; KRISTUKAT, C.; CHARLASSIER, R.; LOUIS, T.; COPPOLECCHIA, A.; MAY, A.; DHEILLY, S.; MELO, D.; ETCHEGOYEN, A.; MUNDO, L.M.; FRACCHIA, D.; NATI, F.; GARCÍA, B.; PAIELLA, A.; GAYER, D.; PELOSI, A.; ZANNONI, M.; GILLES, V.; PIACENTINI, F.; GONZÁLEZ, M.; DE BERNARDIS, P.; PLATINO, M.; HARARI, D.; DE PETRIS, M.; PUDDU, R.; HAMILTON, J.-CH.; JULES, E.; RINGEGNI, P.; LAMAGNA, L.; MARNIEROS, S.; SCHILLACI, A.; MARTY, W.; PASSERINI, A.; SPINELLI, S.; TARTARI, A.; MCCULLOC

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2022 vol. 2022

1475-7516

We present the design, manufacturing and performance of the horn-switch system developed for the technological demonstrator of QUBIC (the Q&U Bolometric Interferometer for Cosmology). This system consists of 64 back-to-back dual-band (150 GHz and 220 GHz) corrugated feed-horns interposed with mechanical switches used to select desired baselines during the instrument self-calibration. We manufactured the horns in aluminum platelets milled by photo-chemical etching and mechanically tightened with screws. The switches are based on steel blades that open and close the waveguide between the back-to-back horns and are operated by miniaturized electromagnets. The measured electromagnetic performance of the feedhorns agrees with simulations. In particular we obtained a return loss around -20 dB up to 230 GHz and beam patterns in agreement with single-mode simulations down to -30 dB. The switches for this prototype were designed and built for the 150 GHz band. In this frequency range we find return and insertion losses consistent with expectations (< -25 dB and ∼-0.1 dB, respectively) and an isolation larger than 70 dB. In this paper we also show the current development status of the feedhorn-switch system for the QUBIC full instrument, based on an array of 400 horn-switch assemblies.