The QUIET telescope at the Chajnantor Observatory, Chile.
The Q/U Imaging ExperimenT (QUIET) is the result of an international collaboration to construct an instrument to observe the Q and U polarization of the Cosmic Microwave Background. QUIET is located at the Llano de Chajnantor Observatory in the Chilean Andes, and is currently in "Phase-I". Phase-I employs a 16-element array at Q-band (40 GHz) and a 91-element array at W-band (90 GHz). Phase-II is currently being proposed and will consist of 19 elements at Ka-band (30 GHz), 55 elements at Q-band (40 GHz) and 1497 elements at W-band (90 GHz). QUIET phase-II will provide competitive constraints on large-scale B-modes down to tensor-to-scalar ratios of approximately 0.01 or better, making it one of the leading CMB polarization experiments of the next generation.