High-Transmittance Beam-Scanning Antenna Based on Double-Layer Quasi-One-Dimensional Periodic Trapezoidal Metallic Lines

This article presents a high radio-frequency (RF) transmittance beam-scanning antenna based on a double-layer quasi-one-dimensional (QOD) structure, realized by periodically loading two trapezoidal metallic lines on both sides of a central feeding structure. The trapezoidal strips are hollowed out to improve RF transmittance. The measured prototype achieves a wide scanning range of 58° over 13.5–18.5 GHz, covering both backward and forward quadrants, with a peak gain of 12.7 dBi and an in-band gain consistently above 5.9 dBi. The measured RF transmittance peaks at nearly 90%, and the experimental results agree closely with the simulations. Compared with conventional two-dimensional (2D) periodic structures, the proposed QOD structure exhibits superior RF transmittance, making it more suitable for electromagnetic stealth device design.