An Extremely Low-Profile Ferrite-Loaded Wideband VHF Antenna Design

A novel, very low-profile wideband antenna operating from 30 to 300 MHz is presented. The maximum diameter and height of this antenna is only 60.96 and 5.08 cm, respectively. This design is composed of a fat grounded metallic plate placed 5.08 cm over a ground plane. Several ferrite bars strategically placed between the plate and ground plane play a critical role in improving the low frequencies gain and pattern at high frequencies. Minimal amount of ferrite was used to keep the antenna´s weight below 9.07 kg. Several antenna prototypes were fabricated and tested at an outdoor range with their gain and patterns agreeing well with simulation results.