École Nationale Supérieure de
Techniques Avancées

Résumé

This report presents the work that I have done on an analytical approximation of a simulation of the beam of the HERA dishes developed in [Fag+20] via a CST simulation. This analytical approximation is built upon another approximation developed in [CBK20], and is mainly focused on the incorporation of polarization eects; it seeks a better fit of the various components of the electric field and the derived power beams. I f ind that, by modulating the existing analytical approximation with an adjusted dipole matrix, one is able to recover polarization structure for the fields, and that the beams show decent fitting. Weighted normalized dierences with the reference beam are in the 5-25% range. Incorporation of these changes into dierent simulation pipelines of the HERA project reveals new polarized behavior that is coherent with the outputs obtained with the reference beam. A direct polynomial fitting on the reference E-fields, fully taking into account the frequency and polarization dimensions, seems required to achieve better results.