Next generation cosmic microwave background (CMB) polarization anisotropy measurements will feature focal plane arrays with more than 600 millimeter-wave detectors. We make use of high-resolution photolithography and wafer-scale etch tools to build planar arrays of corrugated platelet feeds in silicon with highly symmetric beams, low cross-polarization and low side lobes. A compact Au-plated corrugated Si feed designed for 150 GHz operation exhibited performance equivalent to that of electroformed feeds: ~-0.2 dB insertion loss, <-20 dB return loss from 120 GHz to 170 GHz, <-25 dB side lobes and <-23 dB cross-polarization. We are currently fabricating a 50 mm diameter array with 84 horns consisting of 33 Si platelets as a prototype for the SPTpol and ACTpol telescopes. Our fabrication facilities permit arrays up to 150 mm in diameter.
@article{arxiv.1007.0805,
title = {Corrugated Silicon Platelet Feed Horn Array for CMB Polarimetry at 150 GHz},
author = {Joseph W. Britton and John P. Nibarger and Ki Won Yoon and James A. Beall and Dan Becker and Hsiao-Mei Cho and Gene C. Hilton and Johannes Hubmayr and Michael D. Niemack and Kent D. Irwin},
journal= {arXiv preprint arXiv:1007.0805},
year = {2015}
}
Comments
12 pages; SPIE proceedings for Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V (Conference 7741, June 2010, San Diego, CA, USA)