Wideband Dual-Polarized Linear Array of Tightly Coupled Elements

Previous studies on tightly coupled dipole arrays (TCDAs) are mainly focused on 2-D phased arrays, where very wide bandwidth can be achieved as compared to 1-D TCDAs. Moreover, for the dual-polarized case, the inter-element coupling is not sufficient in the polarization along the transverse direction of linear array, which leads to a much narrower bandwidth. In this communication, a wideband dual-polarized tightly coupled dipole linear array (TCDLA) is proposed. A novel vertical parasitic superstrate layer is employed in the dual-polarized linear array to compensate the impedance variation in beam scanning cases. As compared to traditional wide-angle impedance matching layer composed of layered dielectric sheets, the vertical parasitic superstrate layer greatly reduces the weight of the array. Simulation results show that the TCDLA achieves 5:1 bandwidth and 4:1 bandwidth in the vertical polarization and horizontal polarization, respectively, for VSWR <; 3.0:1, while scanning up to ±60°. Prototype for a 1 × 26 linear array is fabricated and measured. Good agreement is achieved between measured and simulation results.