3-D Printed Swastika-Shaped Ultrabroadband Water-Based Microwave Absorber

In this letter, a swastika-shaped ultrabroadband metamaterials absorber is proposed. The designed absorber can be fabricated with the polylactic acid by 3-D printing, and packaged after filling with water. The absorber can achieve greater than 90% absorption in the frequency band of 9.3-49.0 GHz, with a relative bandwidth of 136%, which has been well demonstrated in the microwave experiment. Moreover, it also performs well at wide angles of incidence and the absorption efficiency has almost no obvious changes over the water temperature range of 0 °C-100 °C. The absorber proposed in this letter benefits from ultrawideband absorption, low cost and environment-friendly materials, it can be applied in the fields of electromagnetic (EM) stealth and EM energy harvesting.