Broadband Quasi-Non-Diffractive Wave Generation Method for High-Power Microwave Applications

To meet the stringent requirements of broadband operations, high stability and low dispersion in high-power microwave systems, this paper proposes a broadband linearly polarized quasi-non-diffractive wave generation method based on a filter-equivalent circuit model. A metasurface structure centered at 75 GHz is designed for this method, which enables the generation of linearly polarized quasi-non-diffractive beams in the 60–90 GHz band with a 40% relative bandwidth and a maximum non-diffractive distance of 120 mm. By optimizing the metasurface’s phase response through the equivalent circuit model, the proposed method effectively suppresses the dispersion effects that limit bandwidth utilization in existing designs. Simulation results confirm that the generated beams maintain excellent stability across the entire operating band, with minimal variations in the maximum non-diffractive distance. This work fills the research gap in broadband achromatic linearly polarized quasi-non-diffractive beams, and its relative bandwidth outperforms all previous linear polarization designs. It thus provides a reliable technical solution for long-distance, high-efficiency electromagnetic wave transmission in defense, industrial and medical applications that rely on high-power microwave technology.