Graphene-based Broadband Reflection-type Modulator with Tunable Amplitude

A novel broadband millimeter-wave modulator with tunable reflection amplitude is proposed in this paper. By utilizing graphene-gold metasurface, Si02/pSi/air substrate and an aluminum reflective backplane, a well performance across 25.3-38.2 GHz is achieved. The employment of bias voltage allows the chemical potential of graphene to be switchable and correspondingly the surface resistivity will change as well. When the surface resistivity of graphene varies from 5012/sq to 5000/sq, the reflection amplitude of the modulator can be tuned from 78% to 26% over the whole operation bandwidth. Simulated surface loss density is also shown to give further explanation of physical mechanisms. The broadband tunable modulator has provided a wide application of high performance equipment, such as active electromagnetic cloaking and electro-optic switches.