Coaxial Beam Rotating Antenna (COBRA) Development and Technology Demonstrations

Period of Performance: 01/24/1997 - 05/01/1999


Phase 2 SBIR

Recipient Firm

Voss Scientific
418 Washington St. SE Array
Albuquerque, NM 87108
Principal Investigator


This antenna development effort specifically addresses the military and commercial need for antennas that can be fed directly with azimuthally symmetric output modes typical of many microwave sources (TM01 circular waveguide or TEM coaxial modes for example). Circular polarization, while sacrificing peak electric field, has advantages in electromagnetic coupling, electromagnetic warfare, RADAR, and satellite communication link applications. The successful Phase I program has experimentally shown the qualitative operation of a COBRA prototype, and resulted in publication of Phillips Laboratory Sensor and Simulation Note (SSN No. 395) which documents the theoretical development of COBRA concepts. We propose to take this technology to the next level in Phase II development effort. This will include a comprehensive measurement and characterization of the Phase I COBRA prototype, and detailed engineering study of different COBRA geometries and potential designs, and fabrication of several prototypes. Our plan calls for extensive simulation, modeling, and analysis of four condidate COBRA designs. Then we will optimize and build two fully operational fixed-point (fixed frequency, fixed polarization) COBRA prototypes, and a fully operational, computer controlled, frequency-agile/ polarization-agile COBRA antenna. Finally, we will create a Design Note on the possible design of a fixed-point, high power capable, L-band COBRA antenna. This effort includes full documentation of the effort in the form of monthly reports and a Final report, and presentations of COBRA-related material in peer-reviewed journals and conferences.