Systematic effects introduced by lenses at mm-wavelengths in CMB applications

摘要

Telescopes for the next generation of CMB (Cosmic Microwave Background) experiments could be based on eitherreflective (such as Planck, Clover) or refractive optics (BICEP, LSPE, SPIDER). Both techniques have advantages anddisadvantages. On-axis lens based telescopes can be compact while off-axis reflective configurations can be large. TheRF performances of mirror based telescopes are very well understood, whereas lens based systems have a lowertechnology readiness level: specifically, the systematic effects (aberrations such as chromaticity, birefringence, losses,standing waves and cross-polarisation) that they can introduce need to be accurately quantified at millimetre-wave. Thispaper reports on both RF modelling and preliminary experimental studies of a lens coupled to a feed-horn antenna forwhich the co- and cross-polarisation beam patterns are characterised.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.