Twistreflector Antennas for Airborne HPM Applications

Antennas employing polarization-manipulating and transforming components are now receiving increasing attention within the High-Power Microwave (HPM) DEW community. These aptly-named "transreflectors" and "twistreflectors" are especially suitable in the design of compact and efficient antenna configurations for airborne platforms. During Phase I of this effort, SARA conceived, analyzed, and numerically-modeled several novel trans/twistreflector combinations for potential applications to airborne HPM platforms, including UCAVs and munitions, among others. The most promising configuration we found was for a highly-innovative antenna we call the Flat-Aperture Waveguide Sidewall-Emitting Twistreflector, or "FAWSET." A cylindrical conformal version of the FAWSET should be especially suitable for integration into an HPM-based munition. In that application, the FAWSET should provide a relatively large circumferential aperture with sufficiently-uniform illumination such that even P > 1 GW radiated pulses do not trigger surface-flashover or air-breakdown. By leveraging internal polarization-manipulation, the FAWSET delivers a large aperture with only a modest depth, freeing precious space within the munition for use by the HPM source, pulsed-power, prime power, and other essential subsystems. SARA proposes here to design, build, and demonstrate the successful operation, at peak power levels exceeding 1 GW, of a prototype FAWSET antenna compatible with a munition-type airborne HPM platform.