Novel Plasmonic Antennas for Subterranean Wireless Communications for Counter-WMD Missions

Saltenna has developed several innovative, patented antenna systems which significantly increase capacity for RF signal transmissions through conductive media via efficient excitation of surface electromagnetic waves, which for the sake of brevity are usually called “plasmons”. As illustrated in Fig. 1, our proprietary battery-powered 2.45-GHz transmitting antenna is capable of doing seemingly impossible things: sending video signals from inside a locked -90-dB isolation COTS Faraday cage. This novel capability may be used for improving Wi-Fi connectivity in dense urban environments and underground facilities, such as man-made tunnels and natural caves, as well as remote examination of metal enclosures (such as shipping containers, etc.). In particular, it may be used to provide practical wireless communications which will greatly outperform traditional free-space radio frequency (RF) communications in subterranean environments during DoD missions. It is widely acknowledged that traditional wireless communications links (both RF and non-RF) suffer a number of impairments when used in subterranean spaces. On the other hand, while above-ground free space radio links are well understood, RF propagation underground is not well studied. In particular, only very recently it was recognized that radio frequency surface electromagnetic waves (plasmons) may propagate underground along the boundaries of media having strongly different electric conductivity. Examples of such boundaries may include metal-soil, clay-cement and many other interfaces which are typically found in subterranean environments during DoD missions. Our preliminary experiments indicate that utilization of radio frequency plasmons will considerably improve radio link performance in subterranean environments via improved plasmonic propagation around tunnel curvatures, corners, intersections, and discontinuities. Development of field-proven plasmonic radios proposed by Saltenna will enable DoD missions in subterranean environments, which require the real-time exchange of substantial amounts of information such as voice, video, and sensor data among personnel, sensors, and robotic systems. Technology developed by Saltenna under this SBIR topic will be invaluable to DoD groups conducting counter-WMD missions.