A wide band conformal wide slot antenna on circular cylindrical structure with appropriate feed matching circuit is proposed. The slot antenna is in the shape of a hexagon and is fed capacitively by small parasitic patches. These parasitic patches are fed by a microstrip line. The antenna proposed, with an overall substrate thickness of 1.2mm has at least 62 percent bandwidth over the frequency range of 3.38-6.38GHz. The dependence of design parameters on the bandwidth characteristics is investigated. The simulation via a Finite Difference Time domain method in cylindrical coordinates, and measured results on the return loss and the E and H plane radiation patterns of the proposed antennas are presented and shown to be in good agreement.