Metallised dual dielectric loaded horn

The dielectric cone loaded horns have good potential to be used as high performance feed horns, but they need some means of accurately supporting the dielectric cone in the smooth wall metal horn. The paper reports a new version of the horn which has two novel innovations. Firstly the central foam dielectric cone is surrounded by a second foam dielectric with a lower permittivity. This ensures that the dielectric cone is accurately positioned. Secondly the metal walls are produced by depositing a thin copper layer directly onto the dielectric. This provides the conducting wall for the horn and also reduces the weight of the horn by a significant amount. The result is a horn which is lightweight and compact. The paper describes the theoretical technique used to design the horn and reports a parametric study of the relevant parameters for the dielectric cone loaded horn. The design and manufacture of the new horn is then described together with the measured performance and possible future developments. >