Design of X‐Band Broadband H‐Shaped Slit‐Coupled Microstrip Patch Antenna Array

This paper presents a broadband slit‐coupled antenna design for X‐band applications. By using double‐layer microstrip patches as the unit, high gain and broadband characteristics have been achieved. In array design, by loading open‐circuit branches, the current distribution on the antenna surface was adjusted, thereby reducing the electromagnetic coupling between adjacent units and achieving the expansion of impedance bandwidth. Measurements show a 27.8% impedance bandwidth (9.3–12.3 GHz) with active VSWR < 2. The antenna achieves a maximum gain of 24.98 dBi at 10.8 GHz in the H‐plane, with first sidelobe levels below −17 dB, showing good agreement with simulation predictions.