Pattern measurements of a low-sidelobe horn antenna

Abstract

The power pattern of a corrugated horn antenna designed for low sidelobes was measured to levels 90 dB below the main beam maximum in both the E-and H-planes. The measured patterns were found to be in good agreement with theoretical predictions.

Large Angular Scale Polarization of the Cosmic Microwave Background Radiation and the Feasibility of Its Detection

“…Requiring the total power from these sources to lie below 1 µK demands 75 dB and 63 dB sidelobe rejection for the Sun and Moon, respectively. Assuming 20 dB rejection from the ground screen, this level of rejection can be achieved with the corrugated horn antenna (Janssen et al 1979) if data are rejected when these sources lie closer to the zenith than 50 • and 30 • respectively. Binning of the data in Sun-centered or Moon-centered coordinates will allow us to uncover correlations between the position of these objects and the response of the polarimeter.…”

An Instrument for Investigating the Large Angular Scale Polarization of the Cosmic Microwave Background

“…Due to the absence of supplemental beam-forming reflectors, cross-polarization of the instrument is near the minimum possible level for a millimeter wave receiver. Polar's feed horn design is based on the procedure outlined in Zhang et al (1993), and is similar to the K a -band feed horn employed by the COBE DMR experiment (Janssen et al 1979). The horn exhibits symmetry between its E and H planes and produces a diffraction-limited power response with a ≃ 7 • full-widthat-half-maximum (FWHM) across the band.…”

Water Vapor Radiometry in Geodetic Applications

“…Each channel is fed by a corrugated horn antenna of the type described by Janssen et al (1979) and having a beamwidth of 7 0 (full width at half power) at both frequencies.…”