Militarized Airborne Very Low Frequency (VLF) Receive Antenna

ABSTRACT: For decades, very low frequency (VLF) links have been an important part of Air Force"s worldwide logistics infrastructure and response-coordination capability. With an increasingly-global proliferation of nuclear capability, Air Force faces an urgent need to update legacy VLF equipment to reliably support scenarios where its applicability is vital, including the nuclear command control and communications (NC3) environment where support of resources like the Emergency Action Message (EAM) network would be most critical. Simultaneously, the proliferation of modern technologies with both intentional and unintentional VLF radiation (including switching power electronics and their VLF-radiating magnetic cores) has created an electromagnetic interference (EMI) environment for VLF reception that has never been worse especially in modern airborne environments. In response to these demands, there is an urgent need to update legacy VLF systems to support a more comprehensive set of foreseeable battlefield scenarios. In our proposed approach, FIRST RF leverages established concepts for VLF antenna applications, applies proven techniques for militarization, and combines these into a novel yet pragmatic antenna system architecture that provides unprecedented capability in terms of sensitivity, polarimetric diversity, and both spatial and active interference filtering. BENEFIT: As a result of this SBIR, FIRST RF"s technology will enable robust EMI mitigation in a highly-sensitive VLF receive antenna. The beamforming technology will have applicability to a variety of military and civilian applications, including improved emergency-beacon tracking/geolocation (especially in high-EMI environments), emergency low-data-rate/local communications. The antenna miniaturization techniques will afford applicability of this VLF antenna system to smaller payloads, including Class 1 UAVs, opening a whole new realm of applications, especially for emergency-beacon geolocation.