The Design and EM modeling of a E-Plane Sectoral Horn Antenna for Ultra Wide Band Application on WR-137 and WR-62 standard waveguides are presented in this paper. In E-plane sectoral antenna, the E-Plane is much narrower as the flaring and dimensions of the horn are much greater in that direction. The horn flare angle, horn size, wall thickness, etc of the E-plane sectored horn antenna are examined. The return loss, input impedance, total gain and field pattern of the E-plane sectored horn antenna are observed. The antenna is simulated using ANSOFT HFSS 14.0.