Millimeter-Wave Profiled Corrugated Horns for the Quad Cosmic Background Polarization Experiment

April 2005 • 2005IJIMW..26..505M

Authors • Murphy, J. A. • Gleeson, E. • Cahill, G. • Lanigan, W. • O'Sullivan, C. • Cartwright, E. • Church, S. E. • Hinderks, J. • Kirby, E. • Thompson, K. • Rusholme, B. • Gear, W. K. • Maffei, B. • Ade, P. A. R. • Tucker, C. • Jones, B.

Abstract • In this paper we report on the design and validation process for the profiled corrugated horn antennas, which feed the bolometer array of a cosmology experiment known as QUaD located at the South Pole. This is a cosmic background radiation polarization project, which demands precise knowledge and control of the optical coupling to the signal in order to map the feeble E- and B-polarization mode structure. The system will operate in two millimeter wavelength bands at 100 and 150 GHz. The imaging horn array collects the incoming signal via on-axis front-end optics and a Cassegrain telescope, with a cold stop in front of the array to terminate side-lobe structure at an edge taper of ‑20dB. The corrugated horn design process was undertaken using in-house analytical software tools, based on modal scattering, specially developed for millimeter -wave profiled horn antennas. An important part of the instrument development was the validation of the horn design, in particular to verify low edge taper levels and the required well-defined band edges. Suitable feed horn designs were measured and were found to be in excellent agreement with theoretical predictions.

Links

• ELECTR https://doi.org/10.1007%2Fs10762-005-4069-7