Recent Advances on Wideband Wide Scanning Connected Slot Arrays

Connected slot arrays with artificial dielectric layers (ADLs) are a type of wideband wide-scanning arrays with several favorable properties. A key advantage is the high front-to-back ratio provided by the artificial dielectric, which allows to reduce the distance between the radiating slots and the ground plane. This results in low-profile array designs the can be realized with multi-layer planar printed circuit boards at microwaves and millimeter waves. Another important feature is the anisotropy of the ADLs, which yields wide scanning capability without supporting the propagation of surface waves. An overview of different array designs based on this concept is given here, together with a description of the typical design steps and the achievable performance. An example unit cell is shown, with 10:1 band, maximum scan angle of 60°, and total height lower than a quarter wavelength at the lowest frequency.