Design of a Broadband Polarization-Insensitive Transmitarray

作者：Ke Li, Zhengqi Qu, Zhuang Li, Yuanming Cai, Fuwei Wang, Yuhui Ren · 发表于：IEEE Antennas and Wireless Propagation Letters · 年份：2026 · DOI：10.1109/lawp.2025.3641246

This letter presents a broadband, polarization-insensitive transmitarray based on a multiresonance four-arm spiral unit cell. The proposed unit employs four-arm spiral structures in both the receiving and transmitting layers, interconnected by four metallic vias. The unit cell can receive incident waves with arbitrary polarization while maintaining the same polarization in the transmitted waves. The design achieves a wide operating band from 9 GHz to 19 GHz with transmission coefficient better than −2 dB, while maintain a low profile of only 0.23λ0 (where λ0 is the free-space wavelength at 14 GHz). A 16 × 16 transmitarray prototype based on the proposed unit was designed, fabricated, and measured. Experimental results show a peak gain of 24.89 dBi, a fractional 3 dB gain bandwidth of 45.16%, and aperture efficiencies up to 44.1%. The proposed design combines the advantages of wide bandwidth, low-profile, and polarization insensitivity, showing significant potential for applications in wireless communication systems.