Cross-Polarization characteristics of GORE-TEX slabs... Abstract
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ALMA Memo # 551
Cross-Polarization characteristics of GORE-TEX slabs at band 9 frequencies.
A. M. Barychev, M. Candotti, N. A. Trappe
2006-06-15
GORE-TEX material, commonly used in radomes, is known to be transparent at microwave bands [1]. In ALMA a thin GORE-TEX membrane will cover the aperture through which the RF beam enters the cabin at the primary vertex hole [2]. Slabs of GORE-TEX are also generally employed in windows for intermediate temperature shields inside the cryostat. The purpose of these windows ideally is to allow the beam to pass through them without introducing any alteration of the beam properties. Main concern has to be put on RF loss, but also in cross-polarization efficiency degradation. This report will stress on the results we have obtained in relation of loss of cross-polar efficiency of a linearly polarized beam passing through a GORE-TEX slab, depending on its orientation relative to the direction of polarization of the beam.
Polarization properties of Muporer and Rohacellr were also investigated.
View a pdf version of ALMA Memo #551.
