Wide-Angle Beam-Scanning Millimeter-Wave Linear Antenna Arrays Facilitated by a Slim High Dielectric-Constant Superstrate

This paper presents a new design methodology to achieve exceptional wide-angle beam-scanning performance for linear millimeter-wave (mm-Wave) antenna arrays, e.g., the range of the 3-dB realized gain drop from the peak is larger than ±90°. The innovation lies in the integration of a slim high dielectricconstant superstrate (HDS) on top of a conventional patch antenna arrays. The gap is around 0.14 λ₀. This slim HDS effectively enhances the 3-dB beam-scanning range of the original array from ±60° to ±91°. This significant improvement is achieved through the increased element beamwidth, reduced mutual coupling between elements, and the traveling wave effect, all enabled by the HDS. Theoretical design guideline for antenna array to achieve wideangle scanning and comprehensive operating principal analysis of the HDS is carried out. To verify the concept, two design prototypes, i.e., a 10-element and a 4-element patch array with the PCB-based HDS-mimic metasurfaces (equivalent ε_r = 19) were developed that feature low-cost, high integration and up to ±90° half-power beamwidth (HPBW) scanning coverage. The novel design method is anticipated to find extensive applications in mm- Wave phased array technologies that require extensively broad beam-scanning performance.