Manipulating polarization of electromagnetic waves through controllable metamaterial absorber

In this presentation, we demonstrate an approach to manipulate electromagnetic waves with different polarizations through a controllable metamaterial absorber. The metamaterial absorber designed at 3.3 GHz is proposed by properly integrating resonant unit cells with orthogonal polarization sensitivity onto a dielectric substrate and coupling the unit cells with microwave diodes. Simulation and measurement results show that through tuning the bias voltage on the diodes so as to change the coupling level between the resonant unit cells, the absorption rate is adjustable from nearly perfect absorption to nearly total reflection. Moreover, the proposed absorber can be controlled to selectively absorb one particularly polarized incident waves and reflect the orthogonally polarized ones with different bias voltage combinations. It is found in the measurement that the absorption rate remains over 89% with wide incident angles ranging from 0° - 50°. The proposed structure provides a novel way to realize electrically reconfigurable device for manipulating EM wave polarizations.