Broadband/Multiband Conformal Circular Beam-Steering Array

A new approach for a broadband/multiband conformal circular beam-steering array is presented with both theory and experimental data. The array is low-profile, suitable for conformal mounting on a platform. It has an omnidirectional coverage with a unidirectional beam that aims at a moderate directivity of 5 to 15 dBi. It consists of a center driven element and parasitic surface waveguide elements symmetrically positioned in the periphery, for electronic beam steering and beam forming to enhance RF connectivity and/or spectral efficiency. This array can achieve ultrawideband multiband performance and low-profile conformability unattainable by conventional array approaches. In addition, its cost is estimated to be an order of magnitude lower than that of conventional beam-steering arrays. Breadboard and brassboard development efforts for the array have essentially achieved a bandwidth of 1.0–2.5 GHz. A larger bandwidth is feasible since its driven element has achieved a continuous 10:1 bandwidth, and since the surface waveguide elements could achieve a multioctave bandwidth similar to the broadbanding path from the Yagi-Uda array to the LP array.