CORRUGATED FEED-HORN ARRAYS FOR FUTURE CMB POLARIZATION EXPERIMENTS.

This work presents the design realization and performance of a 7-element prototype array of corrugated feedhorns in W-band. The module is fabricated using a so-called \u201cplatelet\u201d technique by milling Aluminum plates. This technique is suitable for low-cost and scalable high performance applications. Room temperature Return Loss measurements show a low (<-30 dB) reflection over a 20% bandwidth with a maximum matching of -40 dB at 105 GHz for all seven antennas. Beam pattern measurements indicate good repeatability and a low (-30 dB) sidelobe levels. This work is particularly relevant for future Cosmic Microwave Background polarisation measurements, which require large microwave cryogenic detector arrays coupled to high performance corrugated feed horns