A New Unit-Cell Architecture Applied to Active Wide-Angle Scanning Phased Array

In this paper, we propose a unit-cell element suitable designed for wide-angle scanning active phased array antennas. The design method utilizes the sub-array factor theory inside the unit-cell. The generalization shows that the unit-cell architecture can be applied to different elements to improve their embedded radiation pattern. The presented unit-cell is comprised of three similar radiating elements. It consists of one excited element and two unloaded/open passive parasitic ones. The 1 dB beamwidth of the embedded radiation pattern of the designed unit-cell with a miniaturized vivaldi element is around 130
^o
in the E-plane. It results in a gain reduction of -1.2 dB over ±60
^o
scan angles for a linear array. The total array factor of the proposed architecture is similar to the dense arrays with half-wavelength interelement distances and smaller (high-density array), with the same physical size. Another advantage is that the active impedance variation per scan angles has improved in comparison with half-wavelength arrays unit-cell. The number of excited ports is 1/3 of the equivalent high dense array with the same interelement distances. The whole aperture-size of the designed unit-cell is about half-wavelength in which there are three radiating elements with only one excited element.