Closed-to-open conversion of a mm-wave Gaussian Horn antenna

This paper presents an application of the powerful field modal expansion theory, to derive a mm-wave “open” cross-section gaussian horn antenna starting from a standard closed cross section design. The proposed approach is based on the expansion of the open-structure field in the orthonormal basis of the closed structure. The calculation of an inner product between the closed- and open-structures electromagnetic modes allows to mathematically evaluate and control the “distance” between the original closed and the derived open structure. The proposed methodology has been successfully tested by comparing FDTD simulation results between the closed and the open mm-wave TE11-Guassian converter.