Broadband Frequency Reconfigurable Metamaterial Absorber using Switchable Ground Plane

In this paper, we proposed a broadband Frequency reconfigurable metamaterial absorber using a switchable ground plane (SGP). We proposed the multi-layers and a PIN diode of middle layer for the SGP. Because between the top structure and the bottom ground plane determined the resonant frequency, the switchable ground plane is proposed. When the PIN diode of the SGP turns off, the middle layer becomes reactive and bottom ground plane is working as ground plane of the absorber. On the other hand, when the PIN diode of the SGP turns on, the middle layer becomes ground plane and the bottom ground plane does not affect the absorber. The proposed absorber is demonstrated by full-wave simulation and measurement. The fabricated sample with 27 × 27unit cells is measured for the absorption under normal incidence. When the PIN diode of the SGP turns on, the absorption with more than 90% is achieved from 3.5 to 11 GHz. On the other hand, when the PIN diode of the SGP turns off, the absorption with more than 90% is achieved from 1.7 to 5.2 GHz.