Via-based miniaturized rasorber using graphene films

In this work, we present a miniaturized wideband rasorber with good angular stability using via-based metal–graphene structure. The rasorber consists of a compact lossy layer, a frequency-selective surface layer, and an air spacer in the middle. The metal–graphene structure in the lossy layer achieves a tiny period due to multiple metal vias connected with meander lines and open stubs. The graphene resistive films printed on the surface by screen-printing technology realize omnidirectional planar resistors for broadband absorption. The 1-dB transmission band of the rasorber is from 7.27 to 8.01 GHz and the 10-dB reflection band is from 2.54 to 8.58 GHz. Due to its miniaturized unit cell, both the transmission and absorption performance is stable with a large-angle incident wave. The ultra-miniaturized rasorber is fabricated and measured, which demonstrates a wide bandwidth of 108.6% and a small period of 0.05λL with great angular stability, making it a good candidate for bi-station stealth radome applications.