Ultra-wideband arrays

There is a need for ultra-wideband phased arrays for military applications such as multifunction, EW, and ESM systems. This need was addressed on the DARPA reconfigurable aperture (RECAP) program, with a goal of a 10:1 bandwidth array aperture. Previous aperture designs covered 3 or 5:1 bandwidths [Hemmi, C, et al., March 1999, Chio, T.H., et al., Sept. 1999 and June 2000]. On this program we designed array radiating apertures tunable over a 10:1 bandwidth, using RF micro-electromechanical system (MEMS) switches. Design trades addressed multiple tunable approaches, but ultimately a 10:1 instantaneous-bandwidth approach, requiring no tuning, was selected for further development. An array aperture operating from 1.8 to 18 GHz (10:1), with dual polarization and wide-angle scan capability, was designed and demonstrated with hardware measurement.