Electrical tunable L-band absorbing material for two polarisations

An electrical tunable L-band absorbing material for two polarisations is presented. The proposed absorber consists of a metal resonator and four surrounded metal lines which are connected by pin diodes, and exhibits the tunable range of reflectivity reaching to -40 dB for both polarisations. In particular, for TM polarisation, the working frequency is also tunable from 1.9 to 2.1 GHz due to the conversion between two distinct resonance modes supported by the resonator and surrounding lines, respectively.