Abstract:
A type of "sandwich" metamaterial absorber is developed, fabricated and experimentally demonstrated to solve the electromagnetic radiation problem of high frequency and high integration electronic equipment. The metal layer of this structure is printed on both sides of the FR4 substrate, and the two sets of metal strips on the top layer are used to increase the resonance point and realize the expansion of the bandwidth. To understand the electromagnetic wave absorption mechanism, an equivalent circuit model of the metamaterial absorber unit cell is constructed to investigate the absorbing characteristics, and surface current distributions are analyzed at absorption peaks. The size of the unit is only about 0.1
\lambda _L 
×0.1
\lambda _L 
where
\lambda _L 
is the wavelength of the lowest frequency, and the total thickness of the absorber is only 0.062
\lambda _L 
. Simulated and experimental results show that the absorber exhibits absorptivity above 90% from 10 GHz to 18 GHz under different polarization. Measurement results show good agreement with the numerically simulated results. The structure is characterized by miniaturization, ultra-wideband, high absorptivity and polarization-insensitive, which provides a new type of suppression structure for radiation problems of small electronic equipment.