A Switchable Absorber/Reflector Using Liquid Metal

This paper proposes a switchable absorber/reflector using liquid metal (LM). The polymethylmethacrylate (PMMA) structure with channels is loaded above the unit cell. When the LM is injected into the channels, this structure works like a frequency selective absorber (FSA), a reflection band will be introduced in the absorption band. When the channels are empty, this structure exhibits an absorption band (reflection coefficient lower than -10 dB) from 4 to 12.8 GHz. When the LM is injected into the channels, it exhibits two absorption bands cover 3.5 to 6.2 GHz and 8.2 to 13.5 GHz, whereas a reflection band around 7.7 GHz is obtained.