Accurate modelling of anti-resonant dipole antennas using the method of moments

The authors demonstrate that the difficulties encountered when modelling an ti-resonant antennas are primarily due to the conventional variable gap sou rce model which is commonly employed in thin-wire moment method codes. An a lternative source model is introduced, for use in analysing this class of a ntennas, where the essential Feature is that the gap width of the feed regi on remains fixed. The fixed gap model is compared to the variable gap model for both a half-wave dipole, where the variable gap is still a valid sourc e model, and for a Full-wave antiresonant dipole, when the fixed gap source is shown to be superior to the variable gap model.