Difficulties Encountered When Attempting to Validate Thin-Wire Formulations for Linear Dipole Antennas

摘要

When analyzing wire antennas, the "thin-wire" kernel is often used as a convenient approximation to the exact singular kernel in the electric-field integral equation. In this paper, it is shown that the thin-wire kernel is a poor approximation to the true kernel, but its use does yield good values for input impedance over a significant range of parameters (e.g., wire radii, size of subsectional cells). The validity of the thin-wire kernel when used within the electric field integral equation appears to be due to the fact that the approach is often a good approximation to the Extended Boundary Condition (EBC) formulation. Although it is often implied in the literature that use of the thin-wire kernel will produce "convergent" values for input impedance, in actuality there is no guarantee that results improve as more cells are taken along the wire. Despite widespread use of the "thin-wire" kernel, there are inherent difficulties in the validation of codes based on this approximation.