Broadband planar Traveling-Wave Arrays (TWA) with 2-D elements

This paper discusses latest design of broadband planar Traveling-Wave Array (TWA), a class of broadband planar phased array antennas using planar 2-dimensional (2-D) broadband traveling-wave antenna elements closely spaced above a conducting ground plane, for low cost and multioctave bandwidth. The TWA is fundamentally different from the other two 2-D broadband phased arrays: Current Sheet Antenna (CSA) and Fragmented Aperture (FA). TWA arose directly from antenna concept with an inherent ground plane, while CSA and FA evolved from scattering technology. TWA is much thinner and lighter than CSA and FA, roughly by a factor o 5 and 15, respectively. This study employs an empirical design approach based on the technique of Active Element Gain Pattern (AEGP). Measured data showed TWA´s potential for broad bandwidth and wide-angle scan. Some controversies on AEGP in the literature are also clarified.