Abstract: A hybrid MoM-UTD technique is employed to accurately calculate the isolation between wire antennas mounted on a complex electrically large conductive surface combined with the reciprocity theorem. It is difficult to analyze the isolation of antennas influenced by the electrically large system only by using the method of moment (MoM). The uniform geometrical theory of diffraction(UTD) is a kind of high frequency method, and however, it has poor accuracy. The combination of MoM and UTD takes the advantages of both the methods and efficiently solves the problem of an electrically large object. The isolation between wire antennas is computed with the influence of the electrically large cylindrical surface being considered and sweep-frequency results are obtained, which can not be computed only by MoM.

Key words: method of moment, UTD, isolation, wire antenna, electrically large object