Reconfigurable Coaxial Metasurface Radar Absorber Using Varactor Diode Tuning

Metasurfaces can be used as radar absorbers. However, passive metasurfaces are intrinsically limited in their bandwidth-to-thickness ratio. Thus, it is difficult to design a metasurface which is both thin and wideband. To overcome such limitation, we design a reconfigurable metasurface using varactor diodes. Their bias-dependent variable capacitance offer a range of resonance frequencies that can cover most of the VHF-UHF range. Such behavior is here highlighted on a coaxial metasurface by simulation. Reconfigurability is intended to serve as a preliminary step towards time-modulated metasurfaces.