A Lumped-Circuit Model for a Triband Trapped Dipole Array-Part 1: Model Description

Demands on emergency radio frequency (RF) links have shown how important high-frequency (HF) (330 MHz) communications can be for medium to long range. The YagiUda and the log period antenna are among some of the more popular HF antennas. The KLM´s Communications Equipment, Inc., four-element KT-34A antenna is based on both types of antennas and operates in the 10-, 15-, and 20-m bands. It relies on parallel LC-circuits acting as traps to form three desired element lengths. A lumped-circuit model of this type of antenna has been developed based on the dimensions in the original manual. In part 1 we tune this numerical model to approximate the KT-34A and use it to investigate performance over an imperfect ground plane.