Application of the Hybrid Technique to Time Domain Problems

A hybrid technique which formally combines the method of moments with the geometrical theory of diffraction is used to efficiently generate sufficient frequency domain data so that accurate transformation to the time domain can be accomplished via the fast fourier transform. The advantage of the hybrid technique is that it permits one to solve problems that cannot readily be solved by either method alone. For example, the problem of a monopole at the center of a circular disk is considered. The monopole is characterized by the method of moments, and the finite size of the disk is accounted for by geometrical theory of diffraction techniques. The technique applies equally well, however, to antennas on other bodies such as satellites and aircraft and could be used to investigate the electromagnetic pulse (EMP) response of antennas on such bodies.