Transparent Thermally Tunable Microwave Absorber Prototype Based on Patterned VO2 Film
Zhengang Lu, Yilei Zhang, Heyan Wang, Chao Xia, Yunfei Liu, Shuliang Dou, Yao Li, Jiubin Tan
Abstract
Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal, although having a fixed absorption performance limits their applicability. Here, a simple, transparent, thermally tunable microwave absorber is proposed, based on a patterned vanadium dioxide (VO2) film. Numerical calculations and experiments demonstrate that the proposed VO2 absorber has a high optical transmittance of 84.9% at 620 nm; its reflection loss at 15.06 GHz can be thermally tuned from –4.257 to –60.179 dB, and near-unity absorption is achieved at 523.75 K. Adjusting only the patterned VO2 film duty cycle can change the temperature of near-unity absorption. Our VO2 absorber has a simple composition, a high optical transmittance, a thermally tunable microwave absorption performance, a large modulation depth, and an adjustable temperature tuning range, making it promising for application in tunable sensors, thermal emitters, modulators, thermal imaging, bolometers, and photovoltaic devices.