Transportable Rapidly Deployable VLF Communication System

Diversified Technologies, Inc., (DTI) proposes to develop a transportable and rapidly deployable VLF transmitter and antenna designed to radiate 500 kW comprised of a: Helium Balloon, Antenna Top Hat, Litz Antenna/Tether, Specialized Winch, Helix and variometers, and Transmitter Power Amplifiers. The proposed Transmitter Power Amplifiers are based on standard DTI high voltage switching power supplies, which can deliver 250 kW each at frequencies up to 100 kHz. The pulse width modulation can easily be adjusted to control the output power and advanced phase control techniques can be used to cancel 3rd and 5th harmonics.  The power supply switching is directly controlled by a digital version of the MSK waveform.  A large array of ground rods and cables in damp land or, preferably, near-by sea water may be used as ground plane. DTI will utilize our extensive expertise and experience in RF power system technology to develop and demonstrate an affordable, compact, and transportable transmitter and antenna system. Specifically, in Phase I DTI will design a complete transportable VLF transmitter and antenna system, demonstrate a lofted, efficient frequency-scaled antenna at low power, and demonstrate high power from a 19” rack at 24 kHz into a dummy load.  The proof-of-feasibility of a rapid reconstitution capability of a transmitter and antenna system consists of: (a) compact and transportable VLF system (by design, Task 2), (b) lofted antenna with high radiation efficiency (by demonstration, Task 3), and (c) high delivered transmitter power (by demonstration, Task 4). These technical pieces, when taken together, form proof-of-feasibility of a practical transportable VLF transmitter and antenna system for rapid reconstitution of DON VLF communications systems.