A high permittivity ceramic bead on a straight wire transmision line can be used to suppress propagating cable currents at radio frequencies. The finite-difference time domain method was used to perform a full-wave analysis of the cable structure. Position, size and dielectric properties of the bead were varied, and the model produced a measure of the difference between the radiation pattern with and without the test rig.

A parameter sweep revealed a complex structure for the isosurfaces. Despite this, optimisation using Nimrod/O was able to determine the global optimum.

Results are published here.