Parasitic Effect Suppression With Resonance Cancelation for Broadband Absorber/Reflector

This letter exhibits a switchable double-sided absorber/reflector that realizes broadband performance. This structure effectively breaks the limitation of the absorption bandwidth due to the parasitic capacitance of the p-i-n diode through resonance cancelation. First, the
LC
parallel resonance is adapted to inhibit the interference of the parasitic capacitance by connecting the inductance in parallel with the p-i-n diode. Then, a gap capacitance is introduced to increase the resonance frequency and further expand the bandwidth. The double-sided design is applied to avoid the short-circuit phenomenon caused by the parallel connection of the inductor and the p-i-n in the single-sided design. To control the inductance value more precisely, the meander inductor is employed. Finally, the reflectivity of the proposed structure covers broadband of 3.91–9.77 GHz from reflection to below −10 dB under normal incidence by changing the working states. Furthermore, a sample of the proposed structure was manufactured and measured. The measurements are consistent with simulations.