Ferrite-Loaded, Low-Profile Grounded Bowtie-Loop Antenna for VHF Communication

This letter presents a ferrite core-loaded, low-profile antenna for very high frequency (VHF) communication. The proposed antenna takes the form of a magnetic dipole source on a conducting ground for vertical polarization on the integrated mast of a battleship. In practice, a bowtie loop is grounded, and a ferrite core is internally loaded to decrease operating frequencies. The Ferrite core is used for antenna miniaturization, as it stores magnetic energy inside the resonant core of the antenna. The size of the proposed antenna with a housing assembled for stable loading at the mast is 0.12 × 0.053 × 0.0076 [
${\bm{\lambda }}$
³
] with respect to the lowest matched frequency of 36.8 MHz, with a criterion VSWR of less than 3. The measured realized gain at 30 MHz is –16.9 dBi, demonstrating the upward trend across the VHF band and the sufficiently high value given the antenna size. The proposed antenna achieves the highest realized gain at the lowest operating frequency among the previously reported ferrite core-loaded VHF antennas.