Revisiting the waves on a coated cylinder by using surface-impedance model

The results of analytical and numerical study of the modes propagating on a n impedance-surface circular cylinder are communicated. Besides the well-kn own axially symmetric Sommerfeld's mode, another hybrid mode, having a sing le azimuthal variation, can propagate at any frequency, For a realistic cyl indrical conformal antenna, the both wavenumbers are quite comparable. This may cause additional coupling between array antenna elements.