Design and experimental research of the S-band absorber screen based on the bow-tie patch

This paper presents a novel wideband absorber screen in S-Band based on the bow-tie patch periodical array. From the Floquent's theorem, the reflection and transmission wave is composed of a series of Floquet mode as the electromagnetic wave incident upon a periodical structure. The higher Floquet mode will be evanescent wave with the decreasing of the unit cell size, which is benefit for the absorber designing. However, the decrement of the size limits the length the patch in the unit cell, and it could not resonant at a lower frequency. This paper adopts a bow-tie structure in the antenna theory and design a wideband and thin absorber screen. The geometric sizes of the cell are determinate after the optimization by HFSS software. The measurement results exhibit this screen has a wideband covering S-band and over 90% for 10 dB absorption and its depth is about 1/7 wavelength of centre frequency in free space.