Ultrathin L-band Microwave Tunable Metamaterial Absorber

Abstract

We have proposed a practical way to realize tunable metamaterial absorber at L-band microwave frequencies. The proposed absorber has a sandwiched structure composed of metallic resonator with lumped varactors loadings, dielectric substrate and ground plane. The capacitance value of varactors can be adjusted from 0.5 pF to 2.4 pF by controlling the bias voltage, thus leading to a continuous tunability of the absorption peak from 1.26 GHz to 1.67 GHz, with over 90% energy absorption. Moreover, the absorber has an ultrathin thickness which is less than 1/80 the wavelength of the lowest working frequency.