Domain decomposition FDTD algorithm for the analysis of a new type of E-plane sectorial horn with aperture field distribution optimization

In this paper, a universal and efficient approach of domain decomposition finite-difference time-domain FDTD (DD-FDTD) is presented for the analysis of a new type of horn antenna-E-plane sectorial horn with field amplitude taper and phase correction in the aperture. The power fed into the horn is redistributed to achieve the optimal field amplitude distribution in the aperture, and meanwhile the field phase is corrected by metal lens. Compared with conventional E-plane sectorial horns, the new horn antenna takes the advantages of low sidelobe level, short physical length and wide flare angle etc. Moreover, the most important property of this horn is the weak coupling with each other when it is used as the element of a phased array antenna. The field analysis of such a horn antenna is an extremely complicated three-dimensional EM boundary value problem. The domain decomposition FDTD method is presented in this paper to break through the drawback. The whole horn is decomposed into several subdomains and the meshes are created in local coordinates. In the iteration procedure of FDTD, the data are exchanged between adjacent subdomains with overlapped meshes. The aperture field distribution, voltage standing-wave ratio and pattern calculated by the DD-FDTD method are in good agreement with the experimental data.