A shipborne fading reduction antenna system for maritime satellite communications

A reflection multipath fading reduction technique for antenna systems installed on small maritime vessels and used with the Inmarsat system is described. The method is intended to compensate for the broad beamwidth fade due to sea surface reflections at low zenith angles. A circularly polarized antenna is fed by left- and right-hand circularly polarized components. The latter are also features of the elliptically polarized surface reflections. It is shown numerically that the left-hand component (cross-polarized) is stronger than the right-hand component at elevations over 5 deg. Sample calculations demonstrate that the multipath fading can be reduced by using the left-hand component in the presence of rough seas.