Design and numerical simulation of miniaturised COBRA lens horn

Proposed is a novel miniaturisation method of a coaxial beam-rotating antenna (COBRA) lens horn for high power application. Generally, a miniaturised horn increases the phase error at the aperture because of large flare angle which causes gain decrease. However, since the proposed COBRA lens horn compensates phase error with a modified COBRA lens, radiation characteristics such as gain and radiation pattern of the miniaturised COBRA lens horn are similar to the conventional one while the length of the horn is reduced by more than 50%.