Abstract: An omnidirectional antenna system. Implementations may include an antenna having a wire loop and a single ferrite rod loop. The single ferrite rod loop may be oriented substantially parallel to a plane formed by the wire loop. The single ferrite rod loop may include a plurality of windings and a ferrite rod having a length and two ends. The two ends of the ferrite rod may be substantially centered relative to the wire loop. The plurality of windings may be distributed across a majority of the length of the ferrite rod.

Abstract: Systems and methods for communication in enclosed areas. Implementations of a method may include sending a first high frequency (HF) signal using a first HF radio, receiving the first HF signal with a first medium frequency (MF) repeater, converting the first HF signal to an MF signal using the first MF repeater, and sending the MF signal to one or more second MF repeaters located in an enclosed space. The method may include receiving the MF signal with the one or more second MF repeaters, converting the MF signal to a second HF signal using the one or more second MF repeaters, and sending the second HF signal to a second HF radio. Implementations of radio communication systems may utilize MF repeaters with MF antennas which may be omnidirectional.

Abstract: The invention described herein relates to an antenna system which makes use of the waveguide properties of sea ice. The antenna system broadly includes at least one antenna wire extending along and preferably in contact with a sea ice surface for transmitting and receiving substantially vertically polarized radio waves. In a first embodiment, the antenna system has a single antenna wire connected to a tuner at one end and grounded to seawater at a second end. The antenna system also has a second length of wire attached to the tuner. The second wire passes through a hole in the sea ice and is also grounded to the seawater beneath the sea ice. In an alternative embodiment, only the second wire is grounded to the seawater beneath the sea ice. The single antenna wire in this embodiment is ungrounded. In yet another embodiment, the antenna system comprises a dipole antenna wire laying on the surface of the sea ice and being connected to a radio for transmitting and receiving radio signals.

Abstract: A towable broadband submarine antenna system for deployment in the ocean ing operation comprises an antenna element including a metallic termination tip and a length of single conductor buoyant cable. A broadband amplifier connects to the antenna element and provides separate paths for the VLF/LF and the HF/VHF signals with amplification provided only to the HF/VHF signals. The signal from the broadband amplifier is further transmitted on a coaxial cable.

Abstract: A towable broadband submarine antenna system for deployment in the ocean ing operation comprises an antenna element including a metallic termination tip and a length of single conductor buoyant cable. A broadband amplifier connects to the antenna element and provides separate paths for the VLF/LF and the HF/VHF signals with amplification provided only to the HF/VHF signals. The signal from the broadband amplifier is further transmitted on a coaxial cable.

Abstract: A VLF-VHF broadband in-line amplifier forms a portion of a towable buoyant able antenna system that is deployed in seawater from submarines. The amplifier is located between an antenna system and a coaxial cable. The coaxial cable is connected to the submarine. The VLF-VHF broadband in-line amplifier provides substantially uniform amplification for the frequency range of 10 kHz-160 MHz on signals received from the antenna system. The amplified signals are then transmitted to the submarine over the coaxial cable.