Ultra-Wideband Transmission Using Sub-Wavelength Antennas on Airborne Platforms

We propose an STTR Phase II program to build, test and demonstrate a medium power (100 W) prototype VLF transmitter (3-30 kHz) that has been fully designed and simulated in Phase I. The key advantage of our proposed transmitter is the ability to change frequencies anywhere within the VLF band essentially instantaneously, while also removing the need for a top hat or a loading inductor which ordinarily require large and heavy equipment. The same technology may be applicable to other domains where electrically short antennas with high bandwidth and compact size are needed. The challenge of our technology is the requirement for a high-speed and high-power switch. In Phase I, we research the market for solutions, while also proving the technology with a benchtop low-power prototype. Using the results of our market survey we calculate the capabilities for a Phase II demo that would be sufficient to draw interest in follow-on Phase III programs. Our Phase II design is fully specified and designed with vendors in place to provide all the parts. A receiver network is already in place to validate the electromagnetic emissions across the continent. The primary application is airborne VLF transmission, but we will also pursue, via feasibility studies, applications to subsea and subsurface sensing, HF communications, GPS-independent navigation and timing, radiation belt remediation, and others.