A Lumped-Circuit Model for a Triband Trapped Dipole Array-Part II: Stacked Arrays

Abstract

Demands on emergency rf links have shown how important HF (3-30 MHz) communications can be for medium to long range. Efficient triband antennas have been developed and are quite popular for HF communications. In part 1, we described a lumped circuit model of the KLM 4-element KT-34A antenna. Here we consider its larger companion the 6-element KT-34XA and describe retuning the model for operation in the 10-, 15-and 20-m U.S. Army Military Affiliate Radio System (MARS) bands. We retune the parallel LC-circuits acting as "traps" and adjust the element lengths to obtain a "MARS"array. A numerical model of this type of antenna is of interest to study antenna placement and the use of stacked arrays. We compare the radiation pattern of the 6-element KLM and MARS arrays and show examples for a stacked configuration over an imperfect ground plane. The model results for the individual arrays have the expected front and rear main beam angles but when stacked these angles change in a nonintuitive manner.Index Terms-Dipole arrays, high-frequency (HF) radio communication, log periodic antennas, method of moments (MOM), Yagi-Uda arrays.