Blind-Scan Angle Estimation for Surface-Mounted Antenna Arrays Using a Quasi-Analytical Approach

A quasi-analytical approach based on the Eigenmode Projection Technique (EPT) is presented for analyzing surface-wave excitation in printed-circuit board (PCB) antenna arrays. The study investigates introducing air gaps between printed patch antennas—either through a post-lamination process or by employing surface-mounted technology (SMT) antenna components—as a means to extend the array scan range for a fixed element pitch. The proposed EPT formulation offers frequency-independent matrices and avoids spurious modes, enabling efficient and accurate dispersion analysis. Results are validated against full-wave commercial solvers and experimental measurements for arrays operating in the 5G millimeter-wave (mm-wave) new radio (NR) FR2 bands.